Re: tiny script has memory leak
On Friday, 11 May 2012 22:29:39 UTC+1, gry wrote: > sys.version --> '2.6 (r26:66714, Feb 21 2009, 02:16:04) \n[GCC 4.3.2 > [gcc-4_3-branch revision 141291]] > I thought this script would be very lean and fast, but with a large > value for n (like 15), it uses 26G of virtural memory, and things > start to crumble. > > #!/usr/bin/env python > '''write a file of random integers. args are: file-name how-many''' > import sys, random > > f = open(sys.argv[1], 'w') > n = int(sys.argv[2]) > for i in xrange(n): > print >>f, random.randint(0, sys.maxint) > f.close() > > What's using so much memory? > What would be a better way to do this? (aside from checking arg > values and types, I know...) Ran OK for me, python 2.4.1 on Windows 7 Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Gotcha's?
A common one used to be expecting .sort() to return, rather than mutate (as it does). Same with .reverse() - sorted and reversed have this covered, not sure how common a gotcha it is any more. Iain On Wednesday, 4 April 2012 23:34:20 UTC+1, Miki Tebeka wrote: > Greetings, > > I'm going to give a "Python Gotcha's" talk at work. > If you have an interesting/common "Gotcha" (warts/dark corners ...) please > share. > > (Note that I want over http://wiki.python.org/moin/PythonWarts already). > > Thanks, > -- > Miki -- http://mail.python.org/mailman/listinfo/python-list
Re: Code Review
On May 25, 2:44 pm, ad wrote: > On May 25, 4:06 am, Ulrich Eckhardt > wrote: > > > > > ad wrote: > > > Please review the code pasted below. I am wondering what other ways > > > there are of performing the same tasks. > > > On a unix system, you would call "find" with according arguments and then > > handle the found files with "-exec rm ..." or something like that, but I see > > you are on MS Windows. > > > > args = parser.parse_args() > > > > dictKeys = (vars(args)) > > > The first of these looks okay, while I don't get the additional brackets in > > the second one. Another habit I observe here is the Hungarian notation of > > prefixing the type to the name and using camelCaps. PEP 8 (IIRC) has > > something to say on the preferred naming. I'm not 100% against encoding the > > type in the variable name in Python, since it lacks static type checking, I > > would have chosen "key_dict" here though, or, due to the small size of the > > overall program just "keys". > > > > print (HowManyDays) > > > This puzzled me at first, again the useless additional brackets I thought. > > However, in Python 3, "print" is a function, so that is correct. Still, it > > should be "print(foo)" not "print (foo)". > > > > for files in DirListing: > > > > # Get the absolute path of the file name > > > abspath = (os.path.join(WhatDirectory, files)) > > > "files" is just the name of a single file, right? In that case the name is a > > bit confusing. > > > > # Get the date from seven days ago > > > WeekOldFileDate = CurrentTime - DaysToDelete > > > You are repeating this calculation for every file in the loop. > > > > if FileCreationTime < WeekOldFileDate: > > > #check if the object is a file > > > if os.path.isfile(abspath): os.remove(abspath) > > > # It is not a file it is a directory > > > elif os.path.isdir(abspath): shutil.rmtree(abspath) > > > I'm not sure, but I believe you could use shutil.rmtree() for both files and > > directories. In any case, be prepared for the file still being open or > > otherwise read-only, i.e. for having to handle errors. > > > Also, what if a directory is old but the content is new? Would this cause > > the non-old content to be deleted? > > > Cheers! > > > Uli > > > -- > > Domino Laser GmbH > > Geschäftsführer: Thorsten Föcking, Amtsgericht Hamburg HR B62 932 > > Thank you guys very much for the excellent points. I will use this > information as a reference as I write more code and fix up the > existing script. > > Chris, thank you for putting so much time into your post! > > Until we type again... Wrote something to do the same basic thing a little while ago. Less verbose than yours, and it only does files, not folders. If I was going to do folders though, I'd do them by recursing into them and pruning files, and not go by the folder modify date, which I don't think changes the way you think it changes (for example, if a file inside a folder got updated such that it shouln't be deleted it still will be with your code if the folder modify date is old [this is on Windows]) import os, glob, time, sys if len(sys.argv) < 3: print "USAGE: %s " % sys.argv[0] sys.exit(1) pattern = sys.argv[1] days = int(sys.argv[2]) threshold = days * 24 * 60 * 60 t = time.time() for f in glob.glob(pattern): if t - os.stat(f)[9] > threshold: print f os.remove(f) -- http://mail.python.org/mailman/listinfo/python-list
Re: use of index (beginner's question)
On Apr 28, 2:45 am, Chris Angelico wrote: > Incidentally, you're allowed to put the comma on the last item too: > > lists = [ > ['pig', 'horse', 'moose'], > ['62327', '49123', '79115'], > ] > > Often makes for easier maintenance, especially when you append > array/list elements. > > Chris Angelico I did not know this. Very useful! Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Using nested lists and tables
On Oct 28, 2:35 pm, Iain King wrote:
...
> (a) I don't know if the order of resolution is predicated left-to-
> right in the language spec of if it's an implementation detail
> (b) columns[-1].startswith('s') would be better
>
...
Ignore (b), I didn't read the original message properly.
Iain
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Re: Using nested lists and tables
On Oct 28, 2:19 pm, Zeynel wrote:
> On Oct 28, 4:49 am, Peter Otten <__pete...@web.de> wrote:
>
> Thank you this is great; but I don't know how to modify this code so
> that when the user types the string 's' on the form in the app he sees
> what he is typing. So, this will be in GAE. But I have a couple of
> other questions, for learning purposes. Thanks again, for the help.
>
> > ... if columns and columns[-1][0] == s:
>
> Here, how do you compare "columns" (a list?) and columns[-1][0] (an
> item in a list)?
>
It's equivalent to:
if columns:
if columns[-1][0] == s:
dostuff()
i.e. check columns is not empty and then check if the last item
startswith 's'.
(a) I don't know if the order of resolution is predicated left-to-
right in the language spec of if it's an implementation detail
(b) columns[-1].startswith('s') would be better
Iain
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Re: replacing words in HTML file
On Apr 29, 10:38 am, Daniel Fetchinson wrote: > > | > Any idea how I can replace words in a html file? Meaning only the > > | > content will get replace while the html tags, javascript, & css are > > | > remain untouch. > > | > > | I'm not sure what you tried and what you haven't but as a first trial > > | you might want to > > | > > | > > | > > | f = open( 'new.html', 'w' ) > > | f.write( open( 'index.html' ).read( ).replace( 'replace-this', 'with-that' > > ) ) > > | f.close( ) > > | > > | > > > If 'replace-this' occurs inside the javascript etc or happens to be an > > HTML tag name, it will get mangled. The OP didn't want that. > > Correct, that is why I started with "I'm not sure what you tried and > what you haven't but as a first trial you might". For instance if the > OP wants to replace words which he knows are not in javascript and/or > css and he knows that these words are also not in html attribute > names/values, etc, etc, then the above approach would work, in which > case BeautifulSoup is a gigantic overkill. The OP needs to specify > more clearly what he wants, before really useful advice can be given. > > Cheers, > Daniel > Funny, everyone else understood what the OP meant, and useful advice was given. -- http://mail.python.org/mailman/listinfo/python-list
Re: Code redundancy
On Apr 20, 2:43 pm, Alan Harris-Reid
wrote:
> Hi,
>
> During my Python (3.1) programming I often find myself having to repeat
> code such as...
>
> class1.attr1 = 1
> class1.attr2 = 2
> class1.attr3 = 3
> class1.attr4 = 4
> etc.
>
> Is there any way to achieve the same result without having to repeat the
> class1 prefix? Before Python my previous main language was Visual
> Foxpro, which had the syntax...
>
> with class1
> .attr1 = 1
> .attr2 = 2
> .attr3 = 3
> .attr4 = 4
> etc.
> endwith
>
> Is there any equivalent to this in Python?
>
> Any help would be appreciated.
>
> Alan Harris-Reid
The pythonic equivalent of VB 'with' is to assign to a short variable
name, for example '_':
_ = class1
_.attr1 = 1
_.attr2 = 2
_.attr3 = 3
_.attr4 = 4
alternatively, you could use the __setattr__ method:
for attr, value in (
('attr1', 1),
('attr2', 2),
('attr3', 3),
('attr4', 4)):
class1.__setattr__(attr, value)
and to get a bit crunchy, with this your specific example can be
written:
for i in xrange(1, 5):
class1.__setattr__('attr%d' % i, i)
Iain
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Re: Usable street address parser in Python?
On Apr 20, 8:24 am, John Yeung wrote: > My response is similar to John Roth's. It's mainly just sympathy. ;) > > I deal with addresses a lot, and I know that a really good parser is > both rare/expensive to find and difficult to write yourself. We have > commercial, USPS-certified products where I work, and even with those > I've written a good deal of pre-processing and post-processing code, > consisting almost entirely of very silly-looking fixes for special > cases. > > I don't have any experience whatsoever with pyparsing, but I will say > I agree that you should try to get the street type from the end of the > line. Just be aware that it can be valid to leave off the street type > completely. And of course it's a plus if you can handle suites that > are on the same line as the street (which is where the USPS prefers > them to be). > > I would take the approach which John R. seems to be suggesting, which > is to tokenize and then write a whole bunch of very hairy, special- > case-laden logic. ;) I'm almost positive this is what all the > commercial packages are doing, and I have a tough time imagining what > else you could do. Addresses inherently have a high degree of > irregularity. > > Good luck! > > John Y. Not sure on the volume of addresses you're working with, but as an alternative you could try grabbing the zip code, looking up all addresses in that zip code, and then finding whatever one of those address strings most closely resembles your address string (smallest Levenshtein distance?). Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: why (1, 2, 3) > [1, 2, 3] is true?
On Feb 25, 2:03 pm, fat bold cyclop wrote: > > Both are not equal, so the comparison returns an arbitrary result in Py2. > > Thanks, Stefan. If I understand you correctly the comparison is not > valid. > But I wonder if there is any logic behind this (in 2.x). > Is it possible to predict result of this comparison? > > Thanks again, > fbc I haven't looked in the source to check (and I'm almost 100% certain that tuple > list is an implementation detail), but I have not found any pair of tuple and list in which the list is treated as the greater. Possibly related: type(tuple()) is > type(list()). Or, to let the interpreter tell you why (1,2,3) > [1,2,3]: >>> tuple > list True Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Ad hoc lists vs ad hoc tuples
On Jan 27, 10:20 am, Floris Bruynooghe
wrote:
> One thing I ofter wonder is which is better when you just need a
> throwaway sequence: a list or a tuple? E.g.:
>
> if foo in ['some', 'random', 'strings']:
> ...
> if [bool1, bool2, boo3].count(True) != 1:
> ...
>
> (The last one only works with tuples since python 2.6)
>
> Is a list or tuple better or more efficient in these situations?
>
> Regards
> Floris
>
> PS: This is inspired by some of the space-efficiency comments from the
> list.pop(0) discussion.
I tend to use tuples unless using a list makes it easier to read. For
example:
if foo in ('some', 'random', 'strings'):
draw.text((10,30), "WHICH IS WHITE", font=font)
draw.line([(70,25), (85,25), (105,45)])
I've no idea what the performance difference is; I've always assumed
it's negligible.
Iain
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Re: substitution
On Jan 21, 2:18 pm, Wilbert Berendsen wrote:
> Op maandag 18 januari 2010 schreef Adi:
>
> > keys = [(len(key), key) for key in mapping.keys()]
> > keys.sort(reverse=True)
> > keys = [key for (_, key) in keys]
>
> > pattern = "(%s)" % "|".join(keys)
> > repl = lambda x : mapping[x.group(1)]
> > s = "fooxxxbazyyyquuux"
>
> > re.subn(pattern, repl, s)
>
> I managed to make it even shorted, using the key argument for sorted, not
> putting the whole regexp inside parentheses and pre-compiling the regular
> expression:
>
> import re
>
> mapping = {
> "foo" : "bar",
> "baz" : "quux",
> "quuux" : "foo"
>
> }
>
> # sort the keys, longest first, so 'aa' gets matched before 'a', because
> # in Python regexps the first match (going from left to right) in a
> # |-separated group is taken
> keys = sorted(mapping.keys(), key=len)
>
> rx = re.compile("|".join(keys))
> repl = lambda x: mapping[x.group()]
> s = "fooxxxbazyyyquuux"
> rx.sub(repl, s)
>
> One thing remaining: if the replacement keys could contain non-alphanumeric
> characters, they should be escaped using re.escape:
>
> rx = re.compile("|".join(re.escape(key) for key in keys))
>
> Met vriendelijke groet,
> Wilbert Berendsen
>
> --http://www.wilbertberendsen.nl/
> "You must be the change you wish to see in the world."
> -- Mahatma Gandhi
Sorting it isn't the right solution: easier to hold the subs as tuple
pairs and by doing so let the user specify order. Think of the
following subs:
"fooxx" -> "baz"
"oxxx" -> "bar"
does the user want "bazxbazyyyquuux" or "fobarbazyyyquuux"?
Iain
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Re: Symbols as parameters?
On Jan 21, 7:43 am, Martin Drautzburg wrote: > Hello all, > > When passing parameters to a function, you sometimes need a paramter > which can only assume certain values, e.g. > > def move (direction): > ... > If direction can only be "up", "down", "left" or "right", you can solve > this by passing strings, but this is not quite to the point: > > - you could pass invalid strings easily > - you need to quote thigs, which is a nuisance > - the parameter IS REALLY NOT A STRING, but a direction > > Alternatively you could export such symbols, so when you "import *" you > have them available in the caller's namespace. But that forces you > to "import *" which pollutes your namespace. > > What I am really looking for is a way > > - to be able to call move(up) > - having the "up" symbol only in the context of the function call > > So it should look something like this > > ... magic, magic ... > move(up) > ... unmagic, unmagic ... > print up > > This should complain that "up" is not defined during the "print" call, > but not when move() is called. And of course there should be as little > magic as possible. > > Any way to achieve this? class Direction(object): pass def is_direction(d): return type(d)==Direction up = Direction() down = Direction() left = Direction() right = Direction() Now you can do your move(up), print up, etc. You can also check a valid direction was passed in by calling is_direction. 'Course, you can extend this so it does something a little more useful: class Direction(object): def __init__(self, vx=0, vy=0): self.vx = vx self.vy = vy up = Direction(0, -1) down = Direction(0, 1) left = Direction(-1, 0) right = Direction(1, 0) def move(direction): spaceship.x += direction.vx spaceship.y += direction.vy Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: substitution
On Jan 18, 4:26 pm, Steven D'Aprano wrote:
> On Mon, 18 Jan 2010 06:23:44 -0800, Iain King wrote:
> > On Jan 18, 2:17 pm, Adi Eyal wrote:
> [...]
> >> Using regular expressions the answer is short (and sweet)
>
> >> mapping = {
> >> "foo" : "bar",
> >> "baz" : "quux",
> >> "quuux" : "foo"
>
> >> }
>
> >> pattern = "(%s)" % "|".join(mapping.keys())
> >> repl = lambda x : mapping.get(x.group(1), x.group(1))
> >> s = "fooxxxbazyyyquuux"
> >> re.subn(pattern, repl, s)
>
> > Winner! :)
>
> What are the rules for being declared "Winner"? For the simple case
> given, calling s.replace three times is much faster: more than twice as
> fast.
>
> But a bigger problem is that the above "winner" may not work correctly if
> there are conflicts between the target strings (e.g. 'a'->'X',
> 'aa'->'Y'). The problem is that the result you get depends on the order
> of the searches, BUT as given, that order is non-deterministic.
> dict.keys() returns in an arbitrary order, which means the caller can't
> specify the order except by accident. For example:
>
> >>> repl = lambda x : m[x.group(1)]
> >>> m = {'aa': 'Y', 'a': 'X'}
> >>> pattern = "(%s)" % "|".join(m.keys())
> >>> subn(pattern, repl, 'aaa') # expecting 'YX'
>
> ('XXX', 3)
>
> The result that you get using this method will be consistent but
> arbitrary and unpredictable.
>
> For those who care, here's my timing code:
>
> from timeit import Timer
>
> setup = """
> mapping = {"foo" : "bar", "baz" : "quux", "quuux" : "foo"}
> pattern = "(%s)" % "|".join(mapping.keys())
> repl = lambda x : mapping.get(x.group(1), x.group(1))
> repl = lambda x : mapping[x.group(1)]
> s = "fooxxxbazyyyquuux"
> from re import subn
> """
>
> t1 = Timer("subn(pattern, repl, s)", setup)
> t2 = Timer(
> "s.replace('foo', 'bar').replace('baz', 'quux').replace('quuux', 'foo')",
> "s = 'fooxxxbazyyyquuux'")
>
> And the results on my PC:
>
> >>> min(t1.repeat(number=10))
> 1.1273870468139648
> >>> min(t2.repeat(number=10))
>
> 0.49491715431213379
>
> --
> Steven
Adi elicited that response from me because his solution was vastly
more succinct than everything else that had appeared up til that point
while still meeting the OP's requirements. The OP never cared about
overlap between 2 'find' strings, just between the 'find' and
'replace' strings (though I did take it into account in my second post
for the sake of completeness). His code could have been a little
cleaner, I'd have trimmed it to:
mapping = {"foo": "bar", "baz": "quux", "quuux": "foo"}
pattern = "(%s)" % "|".join(mapping)
repl = lambda x : mapping[x.group(1)]
s = "fooxxxbazyyyquuux"
re.subn(pattern, repl, s)
but apart from that was very pythonic: explicit, succinct, and all the
heavy work is done by the module (i.e. in compiled c code in the
majority case of CPython). It can be 'upgraded' to cover the find-
find overlap if you really want (I *believe* regexps will match the
leftmost option in a group first):
subs = [("foo", "bar"), ("baz", "quux"), ("quuux", "foo")]
pattern = "(%s)" % "|".join((x[0] for x in subs))
mapping = dict(subs)
repl = lambda x : mapping[x.group(1)]
s = "fooxxxbazyyyquuux"
re.subn(pattern, repl, s)
Anyway, there's no prize for winning, but by all means: if you think
someone else's code and not a variation on this should win for most
pythonic, then make your nomination :)
Iain
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Re: substitution
On Jan 18, 2:17 pm, Adi Eyal wrote:
> > From: superpollo
> > To:
> > Date: Mon, 18 Jan 2010 11:15:37 +0100
> > Subject: substitution
> > hi.
>
> > what is the most pythonic way to substitute substrings?
>
> > eg: i want to apply:
>
> > foo --> bar
> > baz --> quux
> > quuux --> foo
>
> > so that:
>
> > fooxxxbazyyyquuux --> barxxxquuxyyyfoo
>
> > bye
>
> Using regular expressions the answer is short (and sweet)
>
> mapping = {
> "foo" : "bar",
> "baz" : "quux",
> "quuux" : "foo"
>
> }
>
> pattern = "(%s)" % "|".join(mapping.keys())
> repl = lambda x : mapping.get(x.group(1), x.group(1))
> s = "fooxxxbazyyyquuux"
> re.subn(pattern, repl, s)
Winner! :)
Iain
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Re: substitution
On Jan 18, 12:41 pm, Iain King wrote:
> On Jan 18, 10:21 am, superpollo wrote:
>
>
>
> > superpollo ha scritto:
>
> > > hi.
>
> > > what is the most pythonic way to substitute substrings?
>
> > > eg: i want to apply:
>
> > > foo --> bar
> > > baz --> quux
> > > quuux --> foo
>
> > > so that:
>
> > > fooxxxbazyyyquuux --> barxxxquuxyyyfoo
>
> > > bye
>
> > i explain better:
>
> > say the subs are:
>
> > quuux --> foo
> > foo --> bar
> > baz --> quux
>
> > then i cannot apply the subs in sequence (say, .replace() in a loop),
> > otherwise:
>
> > fooxxxbazyyyquuux --> fooxxxbazyyyfoo --> barxxxbazyyybar -->
> > barxxxquuxyyybar
>
> > not as intended...
>
> Not sure if it's the most pythonic, but I'd probably do it like this:
>
> def token_replace(string, subs):
> subs = dict(subs)
> tokens = {}
> for i, sub in enumerate(subs):
> tokens[sub] = i
> tokens[i] = sub
> current = [string]
> for sub in subs:
> new = []
> for piece in current:
> if type(piece) == str:
> chunks = piece.split(sub)
> new.append(chunks[0])
> for chunk in chunks[1:]:
> new.append(tokens[sub])
> new.append(chunk)
> else:
> new.append(piece)
> current = new
> output = []
> for piece in current:
> if type(piece) == str:
> output.append(piece)
> else:
> output.append(subs[tokens[piece]])
> return ''.join(output)
>
> >>> token_replace("fooxxxbazyyyquuux", [("quuux", "foo"), ("foo", "bar"),
> >>> ("baz", "quux")])
>
> 'barxxxquuxyyyfoo'
>
> I'm sure someone could whittle that down to a handful of list comps...
> Iain
Slightly better (lets you have overlapping search strings, used in the
order they are fed in):
def token_replace(string, subs):
tokens = {}
if type(subs) == dict:
for i, sub in enumerate(subs):
tokens[sub] = i
tokens[i] = subs[sub]
else:
s = []
for i, (k,v) in enumerate(subs):
tokens[k] = i
tokens[i] = v
s.append(k)
subs = s
current = [string]
for sub in subs:
new = []
for piece in current:
if type(piece) == str:
chunks = piece.split(sub)
new.append(chunks[0])
for chunk in chunks[1:]:
new.append(tokens[sub])
new.append(chunk)
else:
new.append(piece)
current = new
output = []
for piece in current:
if type(piece) == str:
output.append(piece)
else:
output.append(tokens[piece])
return ''.join(output)
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Re: substitution
On Jan 18, 10:21 am, superpollo wrote:
> superpollo ha scritto:
>
> > hi.
>
> > what is the most pythonic way to substitute substrings?
>
> > eg: i want to apply:
>
> > foo --> bar
> > baz --> quux
> > quuux --> foo
>
> > so that:
>
> > fooxxxbazyyyquuux --> barxxxquuxyyyfoo
>
> > bye
>
> i explain better:
>
> say the subs are:
>
> quuux --> foo
> foo --> bar
> baz --> quux
>
> then i cannot apply the subs in sequence (say, .replace() in a loop),
> otherwise:
>
> fooxxxbazyyyquuux --> fooxxxbazyyyfoo --> barxxxbazyyybar -->
> barxxxquuxyyybar
>
> not as intended...
Not sure if it's the most pythonic, but I'd probably do it like this:
def token_replace(string, subs):
subs = dict(subs)
tokens = {}
for i, sub in enumerate(subs):
tokens[sub] = i
tokens[i] = sub
current = [string]
for sub in subs:
new = []
for piece in current:
if type(piece) == str:
chunks = piece.split(sub)
new.append(chunks[0])
for chunk in chunks[1:]:
new.append(tokens[sub])
new.append(chunk)
else:
new.append(piece)
current = new
output = []
for piece in current:
if type(piece) == str:
output.append(piece)
else:
output.append(subs[tokens[piece]])
return ''.join(output)
>>> token_replace("fooxxxbazyyyquuux", [("quuux", "foo"), ("foo", "bar"),
>>> ("baz", "quux")])
'barxxxquuxyyyfoo'
I'm sure someone could whittle that down to a handful of list comps...
Iain
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Re: Writing a string.ishex function
On Jan 14, 3:52 pm, chandra wrote: > Folks, > > I am new to Python and could not find a function along the lines of > string.ishex in Python. There is however, a string.hexdigits constant > in the string module. I thought I would enhance the existing modlue > but am unsure how I should go about it. Specifically, I have attempted > this much: > ---cut--- > #! /usr/bin/python > # -*- coding: utf-8 -*- > > import string > > def ishex(string): > ishex = False > for i in string: > if i in string.hexdigits: > ishex = True > else: > ishex = False > break > return ishex > ---cut--- > > Can someone help me get further along please? > > Thanks. better would be: def ishex(s): for c in s: if c not in string.hexdigits: return False return True Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Different number of matches from re.findall and re.split
On Jan 11, 3:35 pm, Jeremy wrote:
> Hello all,
>
> I am using re.split to separate some text into logical structures.
> The trouble is that re.split doesn't find everything while re.findall
> does; i.e.:
>
>
>
> > found = re.findall('^ 1', line, re.MULTILINE)
> > len(found)
> 6439
> > tables = re.split('^ 1', line, re.MULTILINE)
> > len(tables)
> > 1
>
> Can someone explain why these two commands are giving different
> results? I thought I should have the same number of matches (or maybe
> different by 1, but not 6000!)
>
> Thanks,
> Jeremy
re.split doesn't take re.MULTILINE as a flag: it doesn't take any
flags. It does take a maxsplit parameter, which you are passing the
value of re.MULTILINE (which happens to be 8 in my implementation).
Since your pattern is looking for line starts, and your first line
presumably has more splits than the maxsplits you are specifying, your
re.split never finds more than 1.
>>> a
'split(pattern, string, maxsplit=0)\nSplit the source string by
the occurren
ces of the pattern,\nreturning a list containing the resulting
substrings.\n
'
>>> re.split(" ", a, re.MULTILINE)
['split(pattern,', 'string,', 'maxsplit=0)\n', '', '', '', 'Split',
'the', 'sour
ce string by the occurrences of the pattern,\nreturning a list
containing th
e resulting substrings.\n']
>>> re.split(" ", a)
['split(pattern,', 'string,', 'maxsplit=0)\n', '', '', '', 'Split',
'the', 'sour
ce', 'string', 'by', 'the', 'occurrences', 'of', 'the', 'pattern,\n',
'', '', ''
, 'returning', 'a', 'list', 'containing', 'the', 'resulting',
'substrings.\n']
Iain
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Re: The rap against "while True:" loops
On Oct 19, 7:51 am, Hendrik van Rooyen wrote: > On Sunday, 18 October 2009 11:31:19 Paul Rubin wrote: > > > Hendrik van Rooyen writes: > > > Standard Python idiom: > > > > if key in d: > > > d[key] += value > > > else: > > > d[key] = value > > > The issue is that uses two lookups. If that's ok, the more usual idiom is: > > > d[key] = value + d.get(key, 0) > > I was actually just needling Aahz a bit. The point I was trying to make > subliminally, was that there is a relative cost of double lookup for all > cases versus exceptions for some cases. - Depending on the frequency > of "some", I would expect a breakeven point. > > - Hendrik Indeed - the method I use for this (picked up from this newsgroup), is to work out roughly how often you need to make a new record instead of altering a current one, and depending on that use either: if key in d: d[key] += value else: d[key] = value or try: d[key] += value except KeyError: d[key] = value I find both to be easily readable (and the similarity between the two blocks is obvious and, to me at least, pleasing). Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple if-else question
On Sep 30, 7:12 am, Steven D'Aprano wrote: > On Tue, 29 Sep 2009 22:29:10 -0700, John Yeung wrote: > > On Sep 29, 1:15 pm, Carl Banks wrote: > >> Hmm, I wonder if Python should emit a warning if an else is used on a > >> for block with no break inside. I don't think the else can be invoked > >> in any other way. As a bonus it could catch some cases where people > >> mistakenly use it thinking it will execute [only] when there are no > >> iterations. > > > [Edit from Duncan Booth] > > > I would definitely be in favor of a warning. Yes, people should read > > the docs more carefully, and yes, it would cost a certain amount of > > annoyance to implement this. But I don't think it would get in people's > > way if they do know how to use else, > > Of course it would. It would mean that everybody who knows how to use > for...else correctly would have to deal with a totally useless warning. > > > and I think it would cut down on > > the number of questions from mystified beginners, some of whom are much > > more aggressive than this particular OP about claiming that Python is > > broken (when it's actually behaving as designed). > > By raising a warning, you are implying that the behaviour is broken, or > at least suspicious. Warnings mean something needs to be warned against > -- "don't do this". Warnings shouldn't be perfectly legitimate behaviours > on the off-chance that the user is confused. "Warning, are you sure you > want to put the car into reverse? Perhaps you meant neutral?" > > What would the warning say? > > "Warning, you have used a legitimate Python control structure but you > might be confused by it." > > "Warning, did you mean if...else instead of for...else?" > > Then we can add a whole lot of extra warnings to protect newbies who > don't read docs (and probably won't read the warnings either) from > themselves: > > "Warning, did you mean obj(1) instead of obj[1]?" > > "Warning, did you mean def f(object) instead of class f(object)?" > > "Warning, did you mean class f(object) instead of def f(object)?" > > "Warning, did you mean 2*3 instead of 2**3?" > > "Warning, did you mean %s instead of %x?" > > "Warning, we think you're helpless and don't know what you want, perhaps > you should be programming in PHP?" > > I'm sympathetic to the desire to educate the n00bs, and in fact I've even > suggested similar warnings myself. But I've been convinced that this is > the wrong approach. Certainly the language shouldn't assume the > programmer is confused. If this sort of warning belongs anywhere (and > that's a big if), it belongs in an IDE. > > -- > Steven Read the suggestion again - it's not a warning on the for-else structure, it's a warning when the for-else doesn't contain a break; he's theorising that a for-else without a break will always trigger the else, in which case it's almost certainly an error, and having the warning is not a bad idea. However, I assume you can get past the else by raising an exception, so the idea becomes a little muddled - do you warn when there is no break and no explicit raise caught outside the loop? What about an implicit exception? I would guess that code intentionally using an implicit exception to break out of a for loop is in need of a warning (and the author in need of the application of a lart), but I'm sure you could construct a plausible situation where it wouldn't be that bad... Anyway, I'm ambivalently on the fence. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: easy question, how to double a variable
On Sep 23, 7:36 pm, David C Ullrich wrote: > On Tue, 22 Sep 2009 02:34:53 +, Steven D'Aprano wrote: > > On Mon, 21 Sep 2009 13:50:23 -0500, David C Ullrich wrote: > > >> But you actually want to return twice the value. I don't see how to do > >> that. > > > What? > > > Seriously? > > You're saying it _can_ be done in Python? They must have added > something to the standard library again. I mean how can you return > twice a value without a twice function to start with? I've tried. > You'd think > > def twice(n): > return twice(n) > > would work, but I get this really long error message. > > > You're not just yanking the OP's chain??? > > That would be cruel. I mean the guy has enough problems already... Sorry, there is no 'twice' builtin. I think what you are looking for is: def twice(n): return return n Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: remove last 76 letters from string
On Aug 6, 11:34 am, MRAB wrote: > Iain King wrote: > >> print >>nucleotides, seq[-76] > > >> last_part = line.rstrip()[-76 : ] > > > You all mean: seq[:-76] , right? (assuming you've already stripped > > any junk off the end of the string) > > The OP said "cut out the last 76 letters (nucleotides) from each > individual sequence and send them to a new txt file with a similar > format.", ie extract the last 76 letters (in the same format) to a file. So he did. Excuse me while I go eat my other foot. -- http://mail.python.org/mailman/listinfo/python-list
Re: remove last 76 letters from string
> print >>nucleotides, seq[-76] > last_part = line.rstrip()[-76 : ] You all mean: seq[:-76] , right? (assuming you've already stripped any junk off the end of the string) Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Confessions of a Python fanboy
On Jul 31, 4:08 pm, Ethan Furman wrote: > Steven D'Aprano wrote: > > On Thu, 30 Jul 2009 18:47:04 +0100, Tim Rowe wrote: > > >>That and the fact that I couldn't stop laughing for long enough to learn > >>any more when I read in the Pragmatic Programmer's Guide that "Ruby, > >>unlike less flexible languages, lets you alter the value of a constant." > >>Yep, as they say "Bug" = "Undocumented feature"! > > > That's no different from Python's "constant by convention". We don't even > > get a compiler warning! > > That's quite different, actually. Python doesn't claim to have > constants! Can't misinterpret what you can't have, can you? > > [Holds breath while awaiting counter-example... :] > > ~Ethan~ The convention being detailed in PEP8: http://www.python.org/dev/peps/pep-0008/ basically, anything in ALL_CAPS is a constant, assuming you follow those style guidelines. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Confessions of a Python fanboy
On Jul 31, 8:28 am, Steven D'Aprano wrote: > On Thu, 30 Jul 2009 18:06:31 -0500, Robert Kern wrote: > > On 2009-07-30 16:44, r wrote: > >> On Jul 30, 4:29 pm, Emmanuel Surleau wrote: > 1.) No need to use "()" to call a function with no arguments. Python > --> "obj.m2().m3()" --ugly > Ruby --> "obj.m1.m2.m3" -- sweeet! > Man, i must admit i really like this, and your code will look so much > cleaner. > >>> It has benefits - code does look better. It has also significant cons > >>> - it is ambiguous. > >>> For instance: > > >>> a = b > > >>> Is b a variable or a method called without parameter? > > >> Hello Emanuel, > >> Again, who so ever names a method with such a non-descriptive name will > >> get whats coming to him. And if you did for some reason use such a > >> cryptic name as "b", do yourself (and everyone else) a favor and follow > >> it with "()" to denote the method call. Remember when something is > >> optional that means you have an option to use it OR not use it. > > > I believe his point is that it is ambiguous to the compiler, not humans > > reading the code. Python functions and methods are first class objects. > > They can be passed around. If they were auto-called, then you could not > > do this. > > Oh my, "r" is still around is he??? And now he's singing the praises of > Ruby, the language which he treated as the Devil's Spawn when he first > arrived. That's hilarious. > > But back on topic... "r" has missed the point. It's not that a=b is hard > to understand because b is a poor name. The example could have been: > > def factory_function(): > magic = time.time() # or whatever > def inner(): > return magic > return inner > > my_function = factory_function > > It's still ambiguous. Does the programmer intend my_function to become > factory_function itself, or the output of factory_function? Not only that - does 'return inner' return the function inner or the result of function inner? How does ruby pass a function as an object? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: string character count
On Jun 30, 6:27 pm, noydb wrote:
> If I have a string for a file name such that I want to find the number
> of characters to the left of the dot, how can that be done?
>
> I did it this way:
> x = "text12345.txt"
> dot = x.find('.')
> print dot
>
> Was curious to see what method others would use - helps me learn. I
> guess I was most curious to see if it could be done in one line.
>
> And, how would a char count be done with no dot -- like if the string
> were "textstringwithoutdot" or "no dot in text string"?
import os
root, ext = os.path.splitext(x)
print len(root)
or in one line (assuming you've imported os):
print len(os.path.splitext(x)[0])
Iain
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Re: do replacement evenly
On Jun 2, 12:10 pm, oyster wrote:
> I have some strings, and I want to write them into a text files, one
> string one line
> but there is a requirement: every line has a max length of a certain
> number(for example, 10), so I have to replace extra SPACE*3 with
> SPACE*2, at the same time, I want to make the string looks good, so,
> for "I am123456line123456three"(to show the SPACE clearly, I type it
> with a number), the first time, I replace the first SPACE, and get "I
> am23456line123456three", then I must replace at the second SPACE
> block, so I get "I am23456line23456three", and so on, if no SPACE*3
> is found, I have to aString.replace(SPACE*2, SPACE).
> I hope I have stated my case clear.
>
> Then the question is, is there a nice solution?
>
> thanx
Assuming you want to crush all spaces into single space, you can:
while " " in s:
s = s.replace(" ", " ")
readable but not efficient. Better:
s = " ".join((x for x in s.split(" ") if x))
Note that this will strip leading and trailing spaces.
Or you can use regexps:
import re
s = re.sub(" {2,}", " ", s)
Iain
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Re: Adding a Par construct to Python?
On May 19, 10:24 am, Steven D'Aprano
wrote:
> On Mon, 18 May 2009 02:27:06 -0700, jeremy wrote:
> > Let me clarify what I think par, pmap, pfilter and preduce would mean
> > and how they would be implemented.
>
> [...]
>
> Just for fun, I've implemented a parallel-map function, and done a couple
> of tests. Comments, criticism and improvements welcome!
>
> import threading
> import Queue
> import random
> import time
>
> def f(arg): # Simulate a slow function.
> time.sleep(0.5)
> return 3*arg-2
>
> class PMapThread(threading.Thread):
> def __init__(self, clients):
> super(PMapThread, self).__init__()
> self._clients = clients
> def start(self):
> super(PMapThread, self).start()
> def run(self):
> while True:
> try:
> data = self._clients.get_nowait()
> except Queue.Empty:
> break
> target, where, func, arg = data
> result = func(arg)
> target[where] = result
>
> class VerbosePMapThread(threading.Thread):
> def __init__(self, clients):
> super(VerbosePMapThread, self).__init__()
> print "Thread %s created at %s" % (self.getName(), time.ctime())
> def start(self):
> super(VerbosePMapThread, self).start()
> print "Thread %s starting at %s" % (self.getName(), time.ctime())
> def run(self):
> super(VerbosePMapThread, self).run()
> print "Thread %s finished at %s" % (self.getName(), time.ctime())
>
> def pmap(func, seq, verbose=False, numthreads=4):
> size = len(seq)
> results = [None]*size
> if verbose:
> print "Initiating threads"
> thread = VerbosePMapThread
> else:
> thread = PMapThread
> datapool = Queue.Queue(size)
> for i in xrange(size):
> datapool.put( (results, i, f, seq[i]) )
> threads = [PMapThread(datapool) for i in xrange(numthreads)]
> if verbose:
> print "All threads created."
> for t in threads:
> t.start()
> # Block until all threads are done.
> while any([t.isAlive() for t in threads]):
> if verbose:
> time.sleep(0.25)
> print results
> return results
>
> And here's the timing results:
>
> >>> from timeit import Timer
> >>> setup = "from __main__ import pmap, f; data = range(50)"
> >>> min(Timer('map(f, data)', setup).repeat(repeat=5, number=3))
> 74.999755859375
> >>> min(Timer('pmap(f, data)', setup).repeat(repeat=5, number=3))
>
> 20.490942001342773
>
> --
> Steven
I was going to write something like this, but you've beat me to it :)
Slightly different though; rather than have pmap collate everything
together then return it, have it yield results as and when it gets
them and stop iteration when it's done, and rename it to par to keep
the OP happy and you should get something like what he initially
requests (I think):
total = 0
for score in par(f, data):
total += score
Iain
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Re: Any idea to emulate tail -f
On May 5, 7:00 am, Joel Juvenal Rivera Rivera wrote: > I want to make something very similar to the command tail -f (follow a > file), i have been trying with some while True and some microsleeps > (about .1 s); did someone has already done something like this? > > And about the file is the apache acceslog of a site with a lot of > traffic. > > Regards > > joe / Joel Rivera This is very interesting, about using Generator Expressions: http://209.85.229.132/search?q=cache:ZHrV4E0eTI8J:www.dabeaz.com/generators/Generators.pdf Relevant stuff about 'tail -f' is on page 39, but I'd read the whole thing if you can. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Scraping a web page
On Apr 7, 1:44 pm, Tim Chase wrote:
> > f = urllib.urlopen("http://www.google.com";)
> > s = f.read()
>
> > It is working, but it's returning the source of the page. Is there anyway I
> > can get almost a screen capture of the page?
>
> This is the job of a browser -- to render the source HTML. As
> such, you'd want to look into any of the browser-automation
> libraries to hook into IE, FireFox, Opera, or maybe using the
> WebKit/KHTML control. You may then be able to direct it to
> render the HTML into a canvas you can then treat as an image.
>
> Another alternative might be provided by some web-services that
> will render a page as HTML with various browsers and then send
> you the result. However, these are usually either (1)
> asynchronous or (2) paid services (or both).
>
> -tkc
WX can render html.
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Re: Why is lambda allowed as a key in a dict?
On Mar 10, 6:38 am, Daniel Fetchinson wrote: > On 3/9/09, bearophileh...@lycos.com wrote: > > > See here Daniel Fetchinson: > > >http://groups.google.com/group/comp.lang.python/browse_thread/thread/... > > > But be quite careful in using that stuff, it has some traps. > > Thanks a lot for all the helpful replies! > Yes, I should name the unnamed lambda function, or better, just use 'def'. > > Cheers, > Daniel > > -- > Psss, psss, put it down! -http://www.cafepress.com/putitdown Sort of tangenitally; is there any real difference between the outcome of the two following pieces of code? a = lambda x: x+2 def a(x): return x+2 Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: RELEASED Python 3.0 final
On Dec 4, 1:51 am, Barry Warsaw <[EMAIL PROTECTED]> wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > On behalf of the Python development team and the Python community, I > am happy to announce the release of Python 3.0 final. > > Python 3.0 (a.k.a. "Python 3000" or "Py3k") represents a major > milestone in Python's history, and was nearly three years in the > making. This is a new version of the language that is incompatible > with the 2.x line of releases, while remaining true to BDFL Guido van > Rossum's vision. Some things you will notice include: > > * Fixes to many old language warts > * Removal of long deprecated features and redundant syntax > * Improvements in, and a reorganization of, the standard library > * Changes to the details of how built-in objects like strings and > dicts work > * ...and many more new features > > While these changes were made without concern for backward > compatibility, Python 3.0 still remains very much "Pythonic". > > We are confident that Python 3.0 is of the same high quality as our > previous releases, such as the recently announced Python 2.6. We will > continue to support and develop both Python 3 and Python 2 for the > foreseeable future, and you can safely choose either version (or both) > to use in your projects. Which you choose depends on your own needs > and the availability of third-party packages that you depend on. Some > other things to consider: > > * Python 3 has a single Unicode string type; there are no more 8-bit > strings > * The C API has changed considerably in Python 3.0 and third-party > extension modules you rely on may not yet be ported > * Tools are available in both Python 2.6 and 3.0 to help you migrate > your code > * Python 2.6 is backward compatible with earlier Python 2.x releases > > We encourage you to participate in Python 3.0's development process by > joining its mailing list: > > http://mail.python.org/mailman/listinfo/python-3000 > > If you find things in Python 3.0 that are broken or incorrect, please > submit bug reports at: > >http://bugs.python.org/ > > For more information, links to documentation, and downloadable > distributions, see the Python 3.0 website: > >http://www.python.org/download/releases/3.0/ > > Enjoy, > - -Barry > > Barry Warsaw > [EMAIL PROTECTED] > Python 2.6/3.0 Release Manager > (on behalf of the entire python-dev team) > > -BEGIN PGP SIGNATURE- > Version: GnuPG v1.4.9 (Darwin) > > iQCVAwUBSTc3pXEjvBPtnXfVAQI69wP/dPHh8IL3GxziEV9QzlveKG+KyZb2X16x > fxJnTCiXAbiAhT5C+m43OEnbF1PJgMDKtcZ5b7aQb4TQ0mJxISTQh0RfLCpArmlo > tdTbzCLnh13KzB+3sUHCx+MeQNXERoWDV8hLz+4Ae71UsuUGynhtyP7ZJMJDue8j > so2gv3fOMSs= > =vkiy > -END PGP SIGNATURE- Props. I just looked through the What's New and the change log, but I couldn't find the answer to something: has any change been made to how tabs and spaces are used as indentation? Can they still be (inadvisably) mixed in one file? Or, more extremely, has one or the other been abolished? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Obama's Birth Certificate - Demand that US presidential electors investigate Obama's eligibility
On Dec 3, 10:16 am, [EMAIL PROTECTED] wrote: > On Dec 3, 12:53 am, Bryan Olson <[EMAIL PROTECTED]> wrote: > > > > > [EMAIL PROTECTED] wrote: > > > This message is not about the meaningless computer printout called > > > More importantly, it's not about Python. I'm setting follow-ups to > > talk.politics. > > > > "Certification of Live Birth" that Obama propaganda machine calls his > > > "Birth Certificate". The American people are still waiting for a copy > > > of Obama's original birth certificate that includes all his birth > > > information. > > > The document is what Hawaii provides as certified copy of birth record. > > It contains all the information the federal government requires to prove > > citizenship by birth, and it shows that Barack Hussein Obama was born 04 > > August 1961 in Honolulu. See: > > >http://www.factcheck.org/elections-2008/born_in_the_usa.html > > This garbage on factcheck.org is a worthless piece of paper > insufficient to prove a US citizenship much less a natural born one. > You need to have a long version of legitimate birth certificate that > includes all birth information. Hawaii officials never even confirmed > this piece of garbage on factcheck.org > > > > Remind your US presidential electors of their constitutional duty to > > > investigate Obama's natural-born citizen status. > > > > No federal agency like FBI or Secret Service, no Hawaii bureaucrats > > > have ever investigated Obama's birth in Hawaii. Many illegal aliens in > > > USA have official "birth certificates" issued by state bureaucrats on > > > the basis of falsified birth records. > > > Janice Okubo of Hawaii's Department of Health confirmed that the state > > has Obama’s original birth certificate on record: > > >http://hawaii.gov/health/about/pr/2008/08-93.pdf > > > [...] > > Do you have a sufficient IQ to actually grasp what this news release > says? > > All it says is that Hawaii has "Obama’s original birth certificate". > It does not say anything whether this "Obama’s original birth > certificate" is from Hawaii or Kenya or from Indonesia. Under the > Hawaii laws, a parent could use an original birth certificate from > another country to register a child in Hawaii and get today > "Certification of Live Birth". People actually born in Hawaii do not > get such "Certification of Live Birth", they get another document with > different name. > > Considering all the public pressure on Hawaii officials to confirm > Obama's birth in Hawaii, they would start any response with > confirmation that Obama was born in Hawaii. Instead, they give you > carefully worded garbage so that your low IQ brain can swallow it and > Obama propaganda machine can beat into your worthless brain until you > repeat it like a low IQ moron. > > > > > > > > Remind your US presidential electors that they have the legal standing > > > and constitutional duty to investigate Obama's birth in Hawaii by > > > demanding that Obama provide all his original birth records, and a > > > federal agency like FBI or Secret Service fully investigate them. > > > That's not what the Constitution says. US Constitution, Article IV, > > Section 1: "Full Faith and Credit shall be given in each State to the > > public Acts, Records, and judicial Proceedings of every other State. And > > the Congress may by general Laws prescribe the Manner in which such > > Acts, Records and Proceedings shall be proved, and the Effect thereof." > > > These haters seek to make Obama prove his records in ways others have > > not had to, and beyond any manner prescribed by Congress within its > > constitutional authority. > > You do not have enough brain cells to understand anything you just > quoted. > > Get one thing straight for your own self interest! THERE ARE TENS OF > MILLIONS OF GUN OWNERS IN USA ONLY WAITING TO USE THEM ON ANYBODY WHO > THREATENS THE US CONSTITUTION - so better use all your brain cells in > your own self interest to resolve this matter now and not later. Run > to Obama and beg him to release all birth records or things will not > get any better. You are playing with fire. Heh, you're awesome. Keep it up! -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing Modification Time of an Outlook Mail in Python
On Nov 25, 5:11 am, "[EMAIL PROTECTED]"
<[EMAIL PROTECTED]> wrote:
> Hi all,
>I am writing a small application which reads the contents of an
> Outlook Mail using python. I am able to read the contents, subject
> along with senders and receivers of a mail using MAPI objects. But may
> I know how can I get access to the "modification time" or the
> receiving time of an outlook mail in Python. For the others I have
> used message object of MAPI session. Here I am pasting a sample code
> to get an idea of what am I doing.
>
> session = Dispatch("MAPI.session")
> session.Logon('outlook') # MAPI profile name
> inbox = session.Inbox
>
> print "Inbox name is:", inbox.Name
> print "Number of messages:", inbox.Messages.Count
>
> for i in range(inbox.Messages.Count):
> message = inbox.Messages.Item(i + 1)
>
> objSender = message.Sender.Address
> objRecip = message.Recipients.Item(j+1)
>
> Now here I want to access the modification time of each mail. And if
> possible if you can guide me to a place where I can get the elements
> of that message object, that would be helpful.
>
> Please mail back for further information.
> Thanks in advance,
> Venu.
This looks like the API for the Message object:
http://msdn.microsoft.com/en-us/library/ms526130(EXCHG.10).aspx
Looks like you want TimeLastModified
Iain
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Re: Multiple equates
On Nov 25, 11:29 am, Iain King <[EMAIL PROTECTED]> wrote:
> On Nov 17, 7:41 pm, Tim Chase <[EMAIL PROTECTED]> wrote:
>
>
>
> > > It doesn't matter as none of this is valid Python. In Python you have to
> > > write
>
> > > array[x1] = False
> > > array[x2] = False
>
> > Uh...not so much...
>
> > >>> a = [1,2,3,4,5]
> > >>> x1, x2 = 1, 3
> > >>> a[x1] = a[x2] = False
> > >>> a
> > [1, False, 3, False, 5]
>
> > Works for me.
>
> > To the OP, I think rather than cluttering my code, I'd just
> > create a loop
>
> >for i in [x1,x2,x3,x4,...x1024]:
> > a[i] = False
>
> > From Diez's disassembly of it (as an aside, nifty little intro
> > to dis.dis()...thanks, Diez!), it looks like it boils down to "is
> > DUP_TOP faster than LOAD_CONST" because the rest of the
> > operations. At this point, it's pretty nitty-gritty.
>
> > Unless the code is in an inner loop somewhere, the simple loop
> > should be more than fast enough. Without knowing the source of
> > the [x1,...] index variables, it's hard to tell if there's a more
> > optimal way to do this.
>
> > -tkc
>
> The loop is much nicer, especially as your array gets longer. The
> generic:
>
> for i in xrange(array):
> array[i] = False
>
> will set the entire array.
>
> Regarding your original question:
>
> array[x1] = array[x2] = False
>
> array[x1] = False
> array[x2] = False
>
> These two blocks are functionally the same when you are setting to
> True or False (or any immutable), but are not if setting to
> immutables, which could give you some real head-scratching bugs if you
> were unaware of the difference - the first version assigns the same
> object to both names:
>
> >>> array[x1] = array[x2] = []
> >>> array[x1].append("Hi")
> >>> array[x2]
>
> ['Hi']
>
> Iain
...and of course, the second time I say 'immutable' I mean 'mutable'.
Hopefully the example was clearer than the text.
Iain
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Re: Multiple equates
On Nov 17, 7:41 pm, Tim Chase <[EMAIL PROTECTED]> wrote:
> > It doesn't matter as none of this is valid Python. In Python you have to
> > write
>
> > array[x1] = False
> > array[x2] = False
>
> Uh...not so much...
>
> >>> a = [1,2,3,4,5]
> >>> x1, x2 = 1, 3
> >>> a[x1] = a[x2] = False
> >>> a
> [1, False, 3, False, 5]
>
> Works for me.
>
> To the OP, I think rather than cluttering my code, I'd just
> create a loop
>
>for i in [x1,x2,x3,x4,...x1024]:
> a[i] = False
>
> From Diez's disassembly of it (as an aside, nifty little intro
> to dis.dis()...thanks, Diez!), it looks like it boils down to "is
> DUP_TOP faster than LOAD_CONST" because the rest of the
> operations. At this point, it's pretty nitty-gritty.
>
> Unless the code is in an inner loop somewhere, the simple loop
> should be more than fast enough. Without knowing the source of
> the [x1,...] index variables, it's hard to tell if there's a more
> optimal way to do this.
>
> -tkc
The loop is much nicer, especially as your array gets longer. The
generic:
for i in xrange(array):
array[i] = False
will set the entire array.
Regarding your original question:
array[x1] = array[x2] = False
array[x1] = False
array[x2] = False
These two blocks are functionally the same when you are setting to
True or False (or any immutable), but are not if setting to
immutables, which could give you some real head-scratching bugs if you
were unaware of the difference - the first version assigns the same
object to both names:
>>> array[x1] = array[x2] = []
>>> array[x1].append("Hi")
>>> array[x2]
['Hi']
Iain
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Re: use of Queue
On Aug 27, 1:17 pm, Alexandru Mosoi <[EMAIL PROTECTED]> wrote: > On Aug 27, 12:45 pm, Alexandru Mosoi <[EMAIL PROTECTED]> wrote: > > > > > how is Queue intended to be used? I found the following code in python > > manual, but I don't understand how to stop consumers after all items > > have been produced. I tried different approaches but all of them > > seemed incorrect (race, deadlock or duplicating queue functionality) > > > def worker(): > > while True: > > item = q.get() > > do_work(item) > > q.task_done() > > > q = Queue() > > for i in range(num_worker_threads): > > t = Thread(target=worker) > > t.setDaemon(True) > > t.start() > > > for item in source(): > > q.put(item) > > > q.join() # block until all tasks are done > > ok. I think I figured it out :). let me know what you think > > global num_tasks, num_done, queue > num_tasks = 0 > num_done = 0 > queue = Queue() > > # producer > num_tasks += 1 > for i in items: > num_tasks += 1 > queue.put(i) > > num_tasks -= 1 > if num_tasks == num_done: > queue.put(None) > > # consumer > while True: > i = queue.get() > if i is None: > queue.put(None) > break > > # do stuff > > num_done += 1 > if num_done == num_tasks: > queue.put(None) > break Are you sure you want to put the final exit code in the consumer? Shouldn't the producer place a None on the queue when it knows it's finished? The way you have it, the producer could make 1 item, it could get consumed, and the consumer exit before the producer makes item 2. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: How to update value in dictionary?
On Aug 27, 2:40 pm, ssecorp <[EMAIL PROTECTED]> wrote:
> dict.update({"a":1}) SETS the dict item "a" 's value to 1.
>
> i want to increase it by 1. isnt that possible in an easy way? I
> should use a tuple for this?
dict["a"] += 1
Iain
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Re: gridSizer inside a panel element
On Aug 22, 2:09 pm, Gandalf <[EMAIL PROTECTED]> wrote:
> why when I try to insert gridSizer to a panel which already inside
> another panel the gridSizer doesn't work?
>
> this is the code:
>
> panel3= wx.Panel(self, -1, (0, 60), size=(400, 240) ,
> style=wx.SIMPLE_BORDER);
> panel3.SetBackgroundColour('#dadadb')
> panel = wx.Panel(panel3, wx.ID_ANY, style=wx.SIMPLE_BORDER,
> size=(150, 60))
> panel.SetBackgroundColour("#fffFFF")
>
> bmp = wx.ArtProvider.GetBitmap(wx.ART_TIP, wx.ART_OTHER, (16,
> 16))
> inputIco = wx.StaticBitmap(panel, wx.ID_ANY, bmp)
>
> labelThree= wx.StaticText(panel, wx.ID_ANY, 'Hello')
>
> label2=wx.StaticText(panel, wx.ID_ANY, 'Pease, Quite, Hello, Shalom')
> topSizer = wx.BoxSizer(wx.VERTICAL)
> gridSizer = wx.GridSizer(rows=2, cols=1, hgap=5, vgap=5)
> input = wx.BoxSizer(wx.HORIZONTAL)
> output = wx.BoxSizer(wx.HORIZONTAL)
>
> input.Add((20,20), 1, wx.EXPAND) # this is a spacer
> input.Add(inputIco, 0, wx.ALL, 5)
> input.Add(labelThree, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL, 5)
>
> output.Add((20,20), 1, wx.EXPAND) # this is a spacer
>
> output.Add(label2, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL, 5)
>
> gridSizer.Add(input, 0, wx.ALIGN_LEFT)
> gridSizer.Add(output, 0, wx.ALIGN_RIGHT)
>
> topSizer.Add(gridSizer, 0, wx.ALL|wx.EXPAND, 5)
> panel.SetSizer(topSizer)
I'm not sure you can just add sizers together like that. When I'm
doing this I'd make panels for each sub-sizer; so input and output
would be panels rather than the sizers themselves. For example
(untested):
grid = wx.Panel(panel, wx.ID_ANY)
input = wx.Panel(grid, wx.ID_ANY)
inputIco = wx.StaticBitmap(input, wx.ID_ANY, bmp)
labelThree= wx.StaticText(input, wx.ID_ANY, 'Hello')
sz = wx.BoxSizer(wx.HORIZONTAL)
sz.Add((20,20), 1, wx.EXPAND) # this is a spacer
sz.Add(inputIco, 0, wx.ALL, 5)
sz.Add(labelThree, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL, 5)
input.SetSizer(sz)
output = = wx.Panel(grid, wx.ID_ANY)
label2=wx.StaticText(output, wx.ID_ANY, 'Pease, Quite, Hello, Shalom')
sz = wx.BoxSizer(wx.HORIZONTAL)
sz.Add((20,20), 1, wx.EXPAND) # this is a spacer
sz.Add(label2, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL, 5)
output.SetSizer(sz)
sz = wx.GridSizer(rows=2, cols=1, hgap=5, vgap=5)
sz.Add(input, 0, wx.ALIGN_LEFT)
sz.Add(output, 0, wx.ALIGN_RIGHT)
grid.SetSizer(sz)
sz = wx.BoxSizer(wx.VERTICAL)
sz.Add(grid, 0, wx.ALL|wx.EXPAND, 5)
panel.SetSizer(sz)
Iain
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Re: Limits of Metaprogramming
On Aug 4, 5:13 pm, Tomasz Rola <[EMAIL PROTECTED]> wrote: > On Mon, 4 Aug 2008, Wilson wrote: > > " Every sufficiently large application has a poor/incomplete > > implementation ofLISPembedded within it ". > > Yep, this is either exact or very close copy of what I have read. > It's Greenspun's Tenth Rule of Programming: "Any sufficiently complicated C or Fortran program contains an ad-hoc, informally-specified bug-ridden slow implementation of half of Common Lisp." Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Boolean tests [was Re: Attack a sacred Python Cow]
On Jul 31, 7:08 am, "Russ P." <[EMAIL PROTECTED]> wrote: > On Jul 30, 10:43 pm, Erik Max Francis <[EMAIL PROTECTED]> wrote: > > > > > Russ P. wrote: > > > On Jul 30, 9:27 pm, Erik Max Francis <[EMAIL PROTECTED]> wrote: > > >> You're sure going on about a distinction without a difference for a guy > > >> who childishly likes to call other people names. A reasonable person > > >> would have long ago moved on instead of blaming others for not > > >> immediately intuiting your thoughts, rather than straightforwardly > > >> reading your words. Which, by the way, includes at least three people > > >> other than myself. > > > >> But I'll bet the mindless namecalling is really working out for you. > > >> Go, team, go! > > > > You earned the "childish name calling" by acting like a child -- with > > > your petty little game of trying to show that I don't understand a > > > basic concept in Python. As I said, your initial misunderstanding, > > > while silly, was at least forgivable. But your insistence on repeating > > > it time after time is not. It is truly pathetic. > > > Sis, boom, rah rah rah! > > > You're kind of skipping over the point where three other people had the > > same misunderstanding about your original statement and correction, so > > Another whopper, but who's counting? > > > maybe the reader is not the problem but rather the writer, but hey, > > don't let that get in the way of a good public shitfit. > > > You're winning! > > And you're a professional of some sort? Man, I can't even imagine > working in an environment with people like you. I guess I'm pretty > lucky to work with real professionals who don't play petty little > games like the one you played here -- and are still playing. Go ahead, > have the last word, loser -- then get lost. You understand this is usenet, right? Where we can all read the entire thread? So trying to spin the situation just doesn't work? Just checking... Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Attack a sacred Python Cow
On Jul 29, 5:33 am, "Russ P." <[EMAIL PROTECTED]> wrote: > On Jul 28, 8:44 pm, alex23 <[EMAIL PROTECTED]> wrote: > > > On Jul 29, 4:46 am, "Russ P." <[EMAIL PROTECTED]> wrote: > > > > As I said, I could write a pre-processor myself to > > > implement it in less than a day. > > > So WHY DON'T YOU WRITE IT ALREADY? > > I'm working on something else right now if you don't mind, but I'll > get to it in good time. > > Conceptually, the matter is simple. All I need to do is to grab the > first formal argument of each def, then search for occurrences of any > word in the body of the def that starts with a dot, and insert that > first argument in front of it. > > I expect the "hard" part will be breaking up the body of the def into > "words." I could just split each line on white space, except for > situations like > > x+=.zzz > > So I need to account for the fact that operators do not need to be > surrounded by spaces. That's the hardest part I can think of off the > top of my head. > > Maybe I'll encounter an insurmountable problem and realize that the > idea can't work in general. If so, then so be it. Certainly, no one on > this thread has anticipated such a problem. Had someone pointed out an > actual technical problem with the idea, I would have gladly thanked > them. But I got a load of irrelevant crap instead, not to mention > being addressed as "boy." > > > If you're meeting so much resistance to your idea, why not scratch > > your own damn itch and just do it? > > > Or doesn't that afford you as many chances to insult others while > > feeling smugly superior? > > This coming from a guy who insulted my reading comprehension ability > -- when he was the one who was wrong! Are you actually this stupid? I mean, you were entertaining while you were mouthing of and insulting your betters, but now you're gonna complain the second anyone insults you (and I mean, 'boy' - what an insult!). Never mind that you're never gonna get off your ass to write a PEP, which would be rejected on language design grounds anyway (as demonstrated by alex23's link - the one you aren't comprehending). The most irritating thing is that I like the idea of being able to use '.x = 10' type notation (and have been for a long time), but the person arguing for it is an insufferable buffoon who's too dense to understand a cogent argument, never mind make one. So great, thanks, the chances of this (or a VB 'with'-like 'using' keyword) ever making it into the language get smaller every time you fire up your keyboard. Nice work. Iain p.s. am looking forward to your post whining about the invalid reasons your PEP got rejected, in the slim hope you actually write one. -- http://mail.python.org/mailman/listinfo/python-list
Re: Execution speed question
On Jul 25, 4:22 pm, Matthew Fitzgibbons <[EMAIL PROTECTED]> wrote: > It seems like the probability calculation applies to all three equally, > and can therefore be ignored for the simulations. The probability affects (1) more. My reasoning for this being: as probability gets lower the number of times you have to loop over the list increases. (1) always loops over the full list, but with each successive iteration (2) and (3) are looping over smaller and smaller lists. In the end this adds up, with (1) becoming slower than (2), even though it starts out quicker. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Execution speed question
On Jul 25, 3:39 pm, Suresh Pillai <[EMAIL PROTECTED]> wrote: > That's a good comparison for the general question I posed. Thanks. > Although I do believe lists are less than ideal here and a different data > structure should be used. > > To be more specific to my case: > As mentioned in my original post, I also have the specific condition that > one does not know which nodes to turn ON until after all the > probabilities are calculated (lets say we take the top m for example). > In this case, the second and third will perform worse as the second one > will require a remove from the list after the fact and the third will > require another loop through the nodes to build the new list. So you need to loops through twice regardless? i.e. loop once to gather data on off nodes, do some calculation to work out what to turn on, then loop again to turn on the relevant nodes? If so, then I think the functions above remain the same, becoming the 2nd loop. Every iteration you do a first loop over the off_nodes (or them all for (1)) to gather the data on them, perform your calculation, and then perform one of the above functions (minus the setup code at the begining; basically starting at the 'for') as a second loop, with the goes_on function now returning a value based on the calculation (rather than the calculation itself as I had it). Performance should be similar. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Execution speed question
On Jul 25, 1:46 pm, Iain King <[EMAIL PROTECTED]> wrote:
> On Jul 25, 10:57 am, Suresh Pillai <[EMAIL PROTECTED]> wrote:
>
>
>
> > I am performing simulations on networks (graphs). I have a question on
> > speed of execution (assuming very ample memory for now). I simplify the
> > details of my simulation below, as the question I ask applies more
> > generally than my specific case. I would greatly appreciate general
> > feedback in terms of computing and of course considerations specific to
> > implementation in Python.
>
> > The nodes in my network may be ON or OFF. The network starts off with
> > all nodes in the OFF state. I loop through the nodes. For each node
> > that is OFF, I consider some probability of it turning ON based on the
> > states of its neighbours. I MUST GO THROUGH ALL NODES BEFORE DECIDING
> > WHICH ONES TO TURN ON.
>
> > So my question is whether it is faster to
>
> > 1. loop through a list of ALL nodes and check for OFF nodes using ifs
>
> > or to
>
> > 2. loop through a container of OFF nodes and remove from this when they
> > turn ON
>
> or 3. build a new list every iteration intead of deleting from the old
> one:
>
> while processing:
> new_off_list = []
> for x in off_list:
> if goes_on(x):
> on_list.append(x)
> else:
> new_off_list.append(x)
> off_list = new_off_list
> generation += 1
>
> Iain
I was curious to what extent the different methods varied in time, so
I checked it out. Here there are three procedures: test_every which
matches your (1), destructive which matches your (2), and constructive
which is (3) as I've outlined above.
On varying the size of the dataset I get this (probability a node goes
on = 50%):
Length of initial list: 10
Test every: 1.16085492357
Destructive: 2.592310272
Constructive: 0.850312458886
Length of initial list: 20
Test every: 2.48013843287
Destructive: 9.20894689718
Constructive: 1.73562198439
Length of initial list: 40
Test every: 5.00652267447
Destructive: 44.9696004134
Constructive: 3.51687329373
Length of initial list: 80
Test every: 9.67657648655
Destructive: 220.57583941
Constructive: 7.06614485537
and changing the probability that a nodes goes on (dataset size =
20):
Probability goes on: 1/2
Test every: 2.24765364513
Destructive: 9.28801971614
Constructive: 1.62770773816
Probability goes on: 1/4
Test every: 4.77387350904
Destructive: 13.4432467571
Constructive: 3.45467140006
Probability goes on: 1/8
Test every: 11.0514899721
Destructive: 18.4026878278
Constructive: 6.86778036177
Probability goes on: 1/16
Test every: 22.5896021593
Destructive: 25.7784044083
Constructive: 13.8631404605
Probability goes on: 1/32
Test every: 49.7667941179
Destructive: 39.3652502735
Constructive: 27.2527219598
Probability goes on: 1/64
Test every: 91.0523955153
Destructive: 65.7747103963
Constructive: 54.4087322936
Code:
import random
from timeit import Timer
SIZE = 10
MAX = 2
def goes_on(x):
global MAX
return random.randint(1,MAX) == 1
def test_every():
global SIZE
print "Test every:",
nodes = range(SIZE)
is_on = [False for x in xrange(SIZE)]
count = SIZE
while count:
for i,x in enumerate(nodes):
if not is_on[i] and goes_on(x):
is_on[i] = True
count -= 1
def destructive():
global SIZE
print "Destructive:",
off_list = range(SIZE)
on_list = []
count = SIZE
while count:
for i in xrange(len(off_list)-1, -1, -1):
x = off_list[i]
if goes_on(x):
on_list.append(x)
del(off_list[i])
count -= 1
def constructive():
global SIZE
print "Constructive:",
off_list = range(SIZE)
on_list = []
count = SIZE
while count:
new_off_list = []
for x in off_list:
if goes_on(x):
on_list.append(x)
count -= 1
else:
new_off_list.append(x)
off_list = new_off_list
#SIZE = 20
while True:
print "Length of initial list:", SIZE
#print "Probability goes on: 1/%d" % MAX
print Timer("test_every()", "from __main__ import
test_every").timeit(1)
print Timer("destructive()", "from __main__ import
destructive").timeit(1)
print Timer("constructive()", "from __main__ import
constructive").timeit(1)
print
SIZE *= 2
#MAX *= 2
Conclusions:
On size, (2) really doesn't like bigger datasets, taking exponentially
longer as it increases, while (1) and (3) happily increase linearly.
(3) is faster.
On probability it's (1) who's the loser, while (2) and (3)
Re: Execution speed question
On Jul 25, 10:57 am, Suresh Pillai <[EMAIL PROTECTED]> wrote: > I am performing simulations on networks (graphs). I have a question on > speed of execution (assuming very ample memory for now). I simplify the > details of my simulation below, as the question I ask applies more > generally than my specific case. I would greatly appreciate general > feedback in terms of computing and of course considerations specific to > implementation in Python. > > The nodes in my network may be ON or OFF. The network starts off with > all nodes in the OFF state. I loop through the nodes. For each node > that is OFF, I consider some probability of it turning ON based on the > states of its neighbours. I MUST GO THROUGH ALL NODES BEFORE DECIDING > WHICH ONES TO TURN ON. > > So my question is whether it is faster to > > 1. loop through a list of ALL nodes and check for OFF nodes using ifs > > or to > > 2. loop through a container of OFF nodes and remove from this when they > turn ON or 3. build a new list every iteration intead of deleting from the old one: while processing: new_off_list = [] for x in off_list: if goes_on(x): on_list.append(x) else: new_off_list.append(x) off_list = new_off_list generation += 1 Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Written in C?
On Jul 21, 6:58 am, "Krishnakant Mane" <[EMAIL PROTECTED]> wrote: > > First off all c# is absolute rubbish waist of time. if I need to > learn it then I better lern java or pythonfor that matter. and by the > way what is a "real programmer?" The story of a Real Programmer: http://www.pbm.com/~lindahl/mel.html Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Best Python packages?
On Jul 19, 8:56 am, Stefan Behnel <[EMAIL PROTECTED]> wrote: > Iain King wrote: > > Well, if you're looking for a list of excellent 3rd party Python > > libraries, then I can give you the ones I like and use a lot: > [...] > > BeautifulSoup : for real-world (i.e. not-at-all-recommendation- > > compliant) HTML processing > > You forgot lxml.html, which is much faster, more memory friendly and more > feature-rich than BS. > > Stefan Never heard of it :) Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Best Python packages?
On Jul 18, 11:23 am, Ben Sizer <[EMAIL PROTECTED]> wrote: > On Jul 16, 3:31 pm, Fredrik Lundh <[EMAIL PROTECTED]> wrote: > > > Ben Sizer wrote: > > > make my development a lot easier. > > > Knowing what kind of development you do might help, of course. Some > > libraries are excellent in some contexts and suck badly in others... > > Sure. Mostly I'm just interested in what's out there though. In C++ > you have Boost which everybody knows are a source of high quality > libraries, covering a fairly wide set of applications. Obviously > that's more low-level and less application specific, and the Python > standard libs do pretty much everything that is in Boost, but it's > that sort of peer-reviewed and widely-applicable list that I'd like to > see. > > I (attempt to) use TurboGears for web development and that depends on > a whole bunch of libraries - SQLObject, PyProtocols, RuleDispatch, > SimpleJson, FormEncode, etc - and I would never have heard of these if > TurboGears' exposure of its internals wasn't so common. Some of these > are web-specific but some are not. And I'd never know to look for them > specificially, because in many cases it wouldn't occur to me that they > exist. (eg. Object-Relational Mappers like SQLObject may be obvious if > you come from certain areas of IT, but I'd never heard of them before > I started with TurboGears.) > > For what it's worth, my main areas of interest are gaming, multimedia, > and web development. But I just like to hear about anything that > people might use which makes their life a lot easier and which perhaps > is not application specific - like ORMs or something similar. > > > Looking at things that larger projects and distributions use can also be > > a good idea. For example, if you're doing scientific stuff, go directly > > to enthought.com. If you're doing web stuff, look at the libraries big > > Django applications use. Etc. > > Sadly, I know just as little about what major applications are out > there as I do about what libraries are out there! > > -- > Ben Sizer Well, if you're looking for a list of excellent 3rd party Python libraries, then I can give you the ones I like and use a lot: wxPython : powerful GUI library which generates native look & feel PIL : Imaging Library - if you need to manipulate bitmaps pyGame :SDL for python BeautifulSoup : for real-world (i.e. not-at-all-recommendation- compliant) HTML processing Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: start reading from certain line
On Jul 10, 4:54 pm, Iain King <[EMAIL PROTECTED]> wrote:
> On Jul 10, 2:45 pm, jstrick <[EMAIL PROTECTED]> wrote:
>
> > Here's a simple way to do it with a minimum amount of loopiness (don't
> > forget to use 'try-except' or 'with' in real life):
>
> > f = open("item1.txt")
>
> > for preline in f:
> > if "Item 1" in preline:
> > print preline,
> > for goodline in f:
> > # could put an end condition with a 'break' here
> > print goodline,
>
> > f.close()
>
> No
Ignore that
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Re: start reading from certain line
On Jul 10, 2:45 pm, jstrick <[EMAIL PROTECTED]> wrote:
> Here's a simple way to do it with a minimum amount of loopiness (don't
> forget to use 'try-except' or 'with' in real life):
>
> f = open("item1.txt")
>
> for preline in f:
> if "Item 1" in preline:
> print preline,
> for goodline in f:
> # could put an end condition with a 'break' here
> print goodline,
>
> f.close()
No
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Re: How to make python scripts .py executable, not bring up editor
On Jul 7, 10:56 pm, korean_dave <[EMAIL PROTECTED]> wrote: > From command Prompt, i type in a script, "tryme.py". > > This, instead, brings up PythonWin editor and Interactive Window. > > Path variable is "C:\Python24". (I need Python 2.4 installed, not 2.5) > > How do I make it so that the script runs? find a .py file in windows explorer. Right click it->Open With- >Choose Program... Now find your python.exe file (should be in c:\python24), select it, and tick the box that says "Always use the selected program" Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: How to bypass Windows 'cooking' the I/O? (One more time, please) II
On Jul 7, 10:18 am, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote:
> On Mon, 07 Jul 2008 01:03:10 -0700, norseman <[EMAIL PROTECTED]>
> declaimed the following in comp.lang.python:
>
>
>
> > > Normal file I/O sequence:
>
> > > fp = open(target, 'wb')
>
> > > fp.seek(-1, 2)
>
> > > fp.write(record)
>
> > Except it doesn't do that in Windows. See below.
>
> I wouldn't expect that sequence to work on any system... The "w"
> implies "create new file, or truncate existing file to 0-bytes, then
> write data to it" -- with no seeking permitted. You must include the "+"
> to do seeking, and if you want to retain the existing file contents you
> probably need to open with "a+" ("a" for append).
>
> The rest of your situation I won't touch. Other than to wonder why
> the situation hasn't hit any of the various database servers which must
> be operating in binary mode, and perform lots of seeking... Surely
> somewhere out someone else must have encountered a seek crossing an
> apparent mark (which isn't a normal Windows sequence anyway --
> since Windows uses for EOL, I'd have expected to see a problem
> if backing over a )
> --
> Wulfraed Dennis Lee Bieber KD6MOG
> [EMAIL PROTECTED] [EMAIL PROTECTED]
> HTTP://wlfraed.home.netcom.com/
> (Bestiaria Support Staff: [EMAIL PROTECTED])
> HTTP://www.bestiaria.com/
lol @ op not finding the answer to his question in the archives, then
being answered again by someone who doesn't let his answer go in the
archive. How useful.
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Re: Win32.client, DAO.DBEngine and exceeding the file sharing count lock
On Jul 2, 8:13 pm, Tim Golden <[EMAIL PROTECTED]> wrote:
> In case it helps, there's a recipe just shown up
> on the Python Cookbook which at least illustrates
> DAO use:
>
> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/572165
>
> TJG
On Jul 2, 6:30 pm, "M.-A. Lemburg" <[EMAIL PROTECTED]> wrote:
> You could try to use the Access ODBC driver and access the database
> that way via mxODBC. That would be faster as well:
>
> http://www.microsoft.com/technet/prodtechnol/windows2000serv/technolo...
> (scroll down to table 7.1)
>
> Apart from that option and if you are really in need for larger
> transactions, I'd suggest that you move to SQL Server for processing
> (if you can). Access is not really made for heavy-lifting and big
> transactions.
Thanks for the help. I'll check those out, in case there's a
performance gain to be had, but I found that ADO can in fact do
exactly what I want; on the comments of the page I previously linked
to which said ADO couldn't was a posting which refuted some of the
OP's claims; ADO can set some options on it's open connection,
including Max Locks Per Record. My code now looks like this:
self._connection.Open(self._DSN)
if MAX_LOCKS != None:
self._connection.Properties("Jet OLEDB:Max Locks Per File").Value
= MAX_LOCKS
rs = win32com.client.Dispatch(r'ADODB.Recordset')
N.B. I'm writing tools software for a 3rd party app which uses an
Access db as it's output format, so I'm locked in. No way to switch
to SQL server.
Thanks both!
Iain
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Re: Win32.client, DAO.DBEngine and exceeding the file sharing count lock
On Jul 2, 3:29 pm, Tim Golden <[EMAIL PROTECTED]> wrote:
> Iain King wrote:
> > Hi. I'm using the win32 module to access an Access database, but I'm
> > running into the File Sharing lock count as
> > inhttp://support.microsoft.com/kb/815281
> > The solution I'd like to use is the one where you can temporarily
> > override the setting using (if we were in VB):
>
> > DAO.DBEngine.SetOption dbmaxlocksperfile,15000
>
> Really hurried answer:
>
>
> import win32com.client
>
> dao = win32com.client.gencache.EnsureDispatch ("DAO.DBEngine.36")
> dao.SetOption (Option=win32com.client.constants.dbMaxLocksPerFile,
> Value=15000)
>
>
> TJG
Thanks. I found this:
http://blogs.msdn.com/michkap/archive/2007/07/13/3849288.aspx
which outlines some difference between DAO and ADO, including:
"Capability to set and change Jet options without making registry
changes (works in DAO through DBEngine.GetOption and
DBEngine.SetOption, fails in ADO, which has no such analogue)."
Now, I'm pretty sure I tried to use DAO before and failed to get it to
work, but maybe you could look at my code and suggest the DAO
equivalent?
---
self._connection = win32com.client.Dispatch(r'ADODB.Connection')
self._DSN = 'PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA SOURCE='+dbfile+';'
self._connection.Open(self._DSN)
rs = win32com.client.Dispatch(r'ADODB.Recordset')
query = 'SELECT '+field+' FROM '+self.__TABLE
rs.Open(query, self._connection, 1, 3)
while not rs.EOF:
v = function(rs.Fields.Item(0).Value)
if v != RETAIN_VALUE:
rs.Fields.Item(0).Value = v
rs.MoveNext()
rs.Close()
---
aTdHvAaNnKcSe,
Iain
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Win32.client, DAO.DBEngine and exceeding the file sharing count lock
Hi. I'm using the win32 module to access an Access database, but I'm running into the File Sharing lock count as in http://support.microsoft.com/kb/815281 The solution I'd like to use is the one where you can temporarily override the setting using (if we were in VB): DAO.DBEngine.SetOption dbmaxlocksperfile,15000 Can I do this in win32com? I've been using ADO, not DAO, but I have to confess to not knowing exactly what the difference is. I set up my recordset thusly: rs = win32com.client.Dispatch(r'ADODB.Recordset') can I jigger it to increase it's max locks? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Creating A Tuple From A List, Adding To Tuple As You Do
On Jun 5, 1:41 pm, Jeff Nyman <[EMAIL PROTECTED]> wrote:
> Greetings all.
>
> The subject line of this thread is probably one of the worst ever. I
> was trying to encapsulate what I am doing. Based on my new-found
> knowledge from another thread, I'm able to get a list of directories
> and they come to me in the form of a list. Here is an example:
>
> from glob import glob
> DC_List = glob('vcdcflx006\\Flex\\Sites\\*\\')
> DC_List = ['Baltimore', 'Birmingham', 'Cincinnati', 'Cleveland',
> LosAngeles']
>
> (Each element in the DC_List is actually a full directory path, but I
> shortened that in the interest of clarity.)
>
> The problem is that I need to pass this list to a list control in a
> wxWidgets application. In order to do that, I need to pass in a list
> like this:
>
> [ ('Baltimore', ''), ('Birmingham', ''), ('Cincinnati', ''),
> ('Cleveland', ''), ('LosAngeles', '') ]
>
> In other words, each element in the list is a tuple that has an empty
> second string. The problem I'm having is in converting my list above
> to be of this type. I can't do append because that (logically) puts
> everything at the end. I did try this:
>
> for count in range(0, len(DC_List)):
> DC_List.insert(count, '')
>
> Here I was thinking I could insert a '' into the right place after
> each entry in the list. That doesn't quite work. Does anyone have an
> idea of a good approach here? (I did search on tuples and lists and
> while I found a lot of information about both, I couldn't find a
> solution that did what I'm discussing above.)
>
> - Jeff
I know a ton of people have already replied with list comprehensions,
but I figured I'd chime in with one that also strips out the path of
your folders for you (since I'm not sure how you are managing that
just now)
cities = [(os.path.basename(x), '') for x in glob('vcdcflx006\\Flex
\\Sites\\*\\')]
I tend to use / instead of \\ as a folder seperator, it should work
for you (I think):
cities = [(os.path.basename(x), '') for x in glob('//vcdcflx006/Flex/
Sites/*')]
Iain
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Re: Interesting Math Problem
On Jun 4, 9:03 am, "BEES INC" <[EMAIL PROTECTED]> wrote:
> I've been awfully busy programming lately. My Django-based side
> project is coming along well and I hope to have it ready for use in a
> few weeks. Please don't ask more about it, that's really all I can say
> for now. Anyways, I came across an interesting little math problem
> today and was hoping some skilled programmers out there could come up
> with a more elegant solution than mine.
> Problem: Star Ratings
>
> People can rate cheeseburgers on my website with a star rating of 0-5
> stars (whole stars only), 5 being mighty tasty and 0 being disgusting.
> I would like to show the average of everyone's ratings of a particular
> cheeseburger to the nearest half star. I have already calculated the
> average rating as a float (star_sum) and the total number of people
> that rated the particular cheeseburger (num_raters). The result should
> be stored as a float in a variable named "stars."
> My Solution (in Python):
>
> # round to one decimal place and
> # separate into whole and fractional parts
> parts = str(round(star_sum/num_raters, 1)).split('.')
> whole = int(parts[0])
> frac = int(parts[1])
> if frac < 3:
> ___frac = 0
> elif frac > 7:
> ___frac = 0
> ___whole += 1
> else:
> ___frac = 5
> # recombine for a star rating rounded to the half
> stars = float(str(whole)+'.'+str(frac))
>
> Mmmm⦠In-N-Out Burgers⦠Please reply if you've got a better solution.
It'd be easier just to do the whole thing with ints. Represents your
stars by counting half-stars (i.e. 0 = no stars, 1 = half a star, 2 =
1 star, etc). Then you just need to divide by 2 at the end.
stars = round(star_sum/num_raters, 0) / 2.0
Iain
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Re: Python and Flaming Thunder
On May 23, 3:35 am, Charles Hixson <[EMAIL PROTECTED]> wrote: > On Thursday 22 May 2008 13:30:07 Nick Craig-Wood wrote: > > > ... > > >From Armstrong's book: The expression Pattern = Expression causes > > > Expression to be evaluated and the result matched against Pattern. The > > match either succeeds or fails. If the match succeeds any variables > > occurring in Pattern become bound. > > > It is a very powerful idea and one which (along with the concurrency > > and message passing from Erlang) has been implemented for python :- > > > http://candygram.sourceforge.net/ > > > I've been reading the Erlang book and I have to say it has given me a > > lot of insight into python... > > Although when comparing Candygram with Erlang it's worth noting that Candygram > is bound to one processor, where Erlang can operate on multiple processors. > (I'd been planning on using Candygram for a project at one point, but this > made it unusable.) lol, nice name. Also surprisingly relevant to the thread: candygrammar: n. A programming-language grammar that is mostly syntactic sugar; the term is also a play on ‘candygram’. COBOL, Apple's Hypertalk language, and a lot of the so-called ‘4GL’ database languages share this property. The usual intent of such designs is that they be as English- like as possible, on the theory that they will then be easier for unskilled people to program. This intention comes to grief on the reality that syntax isn't what makes programming hard; it's the mental effort and organization required to specify an algorithm precisely that costs. Thus the invariable result is that ‘candygrammar’ languages are just as difficult to program in as terser ones, and far more painful for the experienced hacker. -- http://mail.python.org/mailman/listinfo/python-list
Re: Bug in floating-point addition: is anyone else seeing this?
On May 22, 1:14 am, bukzor <[EMAIL PROTECTED]> wrote: > On May 21, 3:28 pm, Dave Parker <[EMAIL PROTECTED]> wrote: > > > On May 21, 4:21 pm, "Diez B. Roggisch" <[EMAIL PROTECTED]> wrote: > > > > Which is exactly what the python decimal module does. > > > Thank you (and Jerry Hill) for pointing that out. If I want to check > > Flaming Thunder's results against an independent program, I'll know to > > use Python with the decimal module. > > Utterly shameless. You may find a more appreciative (and less antagonised) audience for your language in comp.lang.cobol -- http://mail.python.org/mailman/listinfo/python-list
Re: Rename field in Access DB
On May 14, 4:29 pm, Tim Golden <[EMAIL PROTECTED]> wrote:
> Iain King wrote:
> > I'm manipulating an MS Access db via ADODB with win32com.client. I
> > want to rename a field within a table, but I don't know how to. I
> > assume there is a line of SQL which will do it, but nothing I've tried
> > (from searching) has worked.
> > Basic code:
>
> > import win32com.client
> > connection = win32com.client.Dispatch(r'ADODB.Connection')
> > DSN = 'PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=dbfile.mdb;'
> > connection.Open(DSN)
> > connection.Execute("ALTER TABLE tablename CHANGE from to") #this sql
> > doesn't work
> > connection.Close()
>
>
> import os, sys
> from win32com.client.gencache import EnsureDispatch as Dispatch
>
> DATABASE_FILEPATH = r"c:\temp\test.mdb"
> CONNECTION_STRING = "Provider=Microsoft.Jet.OLEDB.4.0; data Source=%s" % \
> DATABASE_FILEPATH
>
> if os.path.exists (DATABASE_FILEPATH):
>os.remove (DATABASE_FILEPATH)
>
> adox = Dispatch ("ADOX.Catalog")
> adox.Create (CONNECTION_STRING)
> adox = None
>
> db = Dispatch ('ADODB.Connection')
> db.Open (CONNECTION_STRING)
> try:
> db.Execute ('CREATE TABLE dtest (id INT, data INT)')
> db.Execute ('INSERT INTO dtest (id, data) VALUES (1, 2)')
>
> try:
> db.Execute ('SELECT id, newdata FROM dtest')
> except:
> print "FAILED as expected"
> else:
> print "SUCCEEDED unexpectedly"
>
> try:
> db.Execute ('SELECT id, data FROM dtest')
> except:
> print "FAILED unexpectedly"
> else:
> print "SUCCEEDED as expected"
>
> adox = Dispatch ("ADOX.Catalog")
> adox.ActiveConnection = db
> adox.Tables ("dtest").Columns ("data").Name = "newdata"
> adox.Tables.Refresh ()
> finally:
> db.Close ()
>
> db = Dispatch ('ADODB.Connection')
> db.Open (CONNECTION_STRING)
> try:
>
> try:
> db.Execute ('SELECT id, data FROM dtest')
> except:
> print "FAILED as expected"
> else:
> print "SUCCEEDED unexpectedly"
>
> try:
> db.Execute ('SELECT id, newdata FROM dtest')
> except:
> print "FAILED unexpectedly"
> else:
> print "SUCCEEDED as expected"
>
> finally:
>db.Close ()
>
>
>
> TJG
Excellent, many thanks.
Iain
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Re: wxpython dialog - do something after ShowModal()?
On May 14, 9:37 pm, "David C. Ullrich" <[EMAIL PROTECTED]> wrote: > In article > <[EMAIL PROTECTED]>, > Iain King <[EMAIL PROTECTED]> wrote: > > > Hi. I have a modal dialog whcih has a "Browse..." button which pops > > up a file selector. This all works fine, but the first thing the user > > has to do when they open the dialog is select a file, so I would like > > the dialog to automatically call the onBrowse function as soon as the > > dialog opens. However, I don't know how to do this. > > > dlg.ShowModal() > > onBrowse() > > > obviously doesn't work, and neither does the reverse. I was hoping > > that the dialog would throw some kind of "I have been shown" event, > > but it doesn't (as far as I can tell). How do I make the dialog do > > something as soon as it's been shown? > > It's too bad that you found an answer. You _shouldn't_ have your > dialog pop up a file-selection box as soon as it's shown! That's > not the way dialogs usually work, so you're going to confuse > people. > > Instead, first pop up the file-selection box, and then pop up > the dialog (without the Browse button) to do whatever else it > does after you've got the filename. > That's actually what happens - the dialog throws EVT_INIT_DIALOG before it displays itself. Not that I really agree with you. I don't think that a "do such-and-such dialog" appearing with a "Select file for such-and-such" file selector on top of it, the file selector being in focus, is confusing for the user. Actually, I think it'd be friendlier - the user can see where the data from the file is going, so has an immediate reminder of what the (generic) file selector is for. -- http://mail.python.org/mailman/listinfo/python-list
Rename field in Access DB
I'm manipulating an MS Access db via ADODB with win32com.client. I
want to rename a field within a table, but I don't know how to. I
assume there is a line of SQL which will do it, but nothing I've tried
(from searching) has worked.
Basic code:
import win32com.client
connection = win32com.client.Dispatch(r'ADODB.Connection')
DSN = 'PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=dbfile.mdb;'
connection.Open(DSN)
connection.Execute("ALTER TABLE tablename CHANGE from to") #this sql
doesn't work
connection.Close()
Anyone know how to get this to work?
Iain
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Re: wxpython dialog - do something after ShowModal()?
On May 13, 2:43 pm, Iain King <[EMAIL PROTECTED]> wrote: > On May 13, 2:20 pm, Larry Bates <[EMAIL PROTECTED]> wrote: > > > > > Iain King wrote: > > > Hi. I have a modal dialog whcih has a "Browse..." button which pops > > > up a file selector. This all works fine, but the first thing the user > > > has to do when they open the dialog is select a file, so I would like > > > the dialog to automatically call the onBrowse function as soon as the > > > dialog opens. However, I don't know how to do this. > > > > dlg.ShowModal() > > > onBrowse() > > > > obviously doesn't work, and neither does the reverse. I was hoping > > > that the dialog would throw some kind of "I have been shown" event, > > > but it doesn't (as far as I can tell). How do I make the dialog do > > > something as soon as it's been shown? > > > > Iain > > > If the only things on your modal dialog are Browse and cancel, just call the > > wx.FileDialog directly and eliminate the intermediate modal dialog. If not > > don't bind the FileDialog to a button, just create an instance of it as the > > last > > you do in the __init__ method of the modal dialog code. > > > If this doesn't help, you will have better luck posting to wxpython > > newsgroup. > > > -Larry > > The dialog doesn't only let you call the file dialog, it does other > stuff too. Your suggestion of __init__ sounded promising, but neither > giving the dialog an __init__() method nor an OnInit() method worked. > Thanks anyway. > > Iain After having a hunt through the wxpython mailing list archives I found the answer: the event is EVT_INIT_DIALOG: dlg.Bind(wx.EVT_INIT_DIALOG, onInit, dlg) work. Thanks for the pointer. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: wxpython dialog - do something after ShowModal()?
On May 13, 2:20 pm, Larry Bates <[EMAIL PROTECTED]> wrote: > Iain King wrote: > > Hi. I have a modal dialog whcih has a "Browse..." button which pops > > up a file selector. This all works fine, but the first thing the user > > has to do when they open the dialog is select a file, so I would like > > the dialog to automatically call the onBrowse function as soon as the > > dialog opens. However, I don't know how to do this. > > > dlg.ShowModal() > > onBrowse() > > > obviously doesn't work, and neither does the reverse. I was hoping > > that the dialog would throw some kind of "I have been shown" event, > > but it doesn't (as far as I can tell). How do I make the dialog do > > something as soon as it's been shown? > > > Iain > > If the only things on your modal dialog are Browse and cancel, just call the > wx.FileDialog directly and eliminate the intermediate modal dialog. If not > don't bind the FileDialog to a button, just create an instance of it as the > last > you do in the __init__ method of the modal dialog code. > > If this doesn't help, you will have better luck posting to wxpython newsgroup. > > -Larry The dialog doesn't only let you call the file dialog, it does other stuff too. Your suggestion of __init__ sounded promising, but neither giving the dialog an __init__() method nor an OnInit() method worked. Thanks anyway. Iain -- http://mail.python.org/mailman/listinfo/python-list
wxpython dialog - do something after ShowModal()?
Hi. I have a modal dialog whcih has a "Browse..." button which pops up a file selector. This all works fine, but the first thing the user has to do when they open the dialog is select a file, so I would like the dialog to automatically call the onBrowse function as soon as the dialog opens. However, I don't know how to do this. dlg.ShowModal() onBrowse() obviously doesn't work, and neither does the reverse. I was hoping that the dialog would throw some kind of "I have been shown" event, but it doesn't (as far as I can tell). How do I make the dialog do something as soon as it's been shown? Iain -- http://mail.python.org/mailman/listinfo/python-list
Splitting MainWindow Class over several modules.
Until recently almost all my python programs were held 1 file for 1 program. This had grown unwieldy for one of my projects, so i decided to refactor it, and ended up with something like this: --- import wx import options import gui import scf class MainWindow(wx.Frame): def __init__(self): self.title = "SFtools v%s" % VERSION wx.Frame.__init__(self, None, wx.ID_ANY, self.title, size=(800,600)) self.SetMinSize((800,600)) readOptions = options.readOptions writeOptions = options.writeOptions createBindings = gui.createBindings createControls = gui.createControls createMenus = gui.createMenus reportError = gui.reportError loadSCF = scf.loadSCF onOpen= scf.onOpen reloadSCF = scf.reloadSCF setMenuMode = scf.setMenuMode unloadSCF = scf.unloadSCF --- Now, this works fine. I like how it reads and that everything being imported can be clearly seen. I have this funny feeling though, that this isn't the standard way of doing this. What is? And is there anything about doing it this way which could be detrimental? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Wxpython. Is it possible to change layout in a running application? Selfmade listbox
On Apr 7, 12:50 pm, Soren <[EMAIL PROTECTED]> wrote: > Hi, > > Id like to make my own special listbox.. I want to able (at the push > of a button) to add another item to my special listbox... each item is > a panel with a label, some buttons and maybe a text control. > > I've tried adding a new panel object with the stuff i want to the > sizer i'm using for my listbox (which is a panel which can contain > other panels)... and then run update() and refresh() on everything... > But it doesn't work.. i see a panel appearing, but it's just a small > square in the corner of my "listbox" panel, and it only works the > first time... nothing new appears when I push the button again. > > Is it at all possible to do this? Has anyone created something > similar? Does anyone know what i'm doing wrong? > > Thanks, > Soren Without your code can only really guess, but I'd check that the new panel you are trying to add to the sizer has the listbox as a parent. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: String To List
On Mar 17, 9:27 am, Iain King <[EMAIL PROTECTED]> wrote:
> On Mar 17, 6:56 am, Dan Bishop <[EMAIL PROTECTED]> wrote:
>
> > On Mar 17, 1:15 am, Girish <[EMAIL PROTECTED]> wrote:
>
> > > I have a string a = "['xyz', 'abc']".. I would like to convert it to a
> > > list with elements 'xyz' and 'abc'. Is there any simple solution for
> > > this??
> > > Thanks for the help...
>
> > eval(a) will do the job, but you have to be very careful about using
> > that function. An alternative is
>
> > [s.strip('\'"') for s in a.strip('[]').split(', ')]
>
> This will fall over if xyz or abc include any of the characters your
> stripping/splitting on (e.g if xyz is actually "To be or not to be,
> that is the question"). Unless you can guarantee they won't, you'll
> need to write (or rather use) a parser that understands the syntax.
>
> Iain
Thinking about this some more; could the string module not use a
simple tokenizer method? I know that relentlessly adding features to
built-ins is a bad idea, so I'm not sure if this falls within
batteries-included, or is actually just adding bulk. On the one hand,
it's not difficult to write a simple state-based token parser
yourself, but on the other it is also quite easy to include a pile of
bugs when you do. By simple I mean something like:
def tokenize(string, delim, closing_delim=None, escape_char=None)
which would return a list (or a generator) of all the parts of the
string enclosed by delim (or which begin with delim and end with
closing_delim if closing_delim is set), ignoring any delimiters which
have been escaped by escape_char. Throw an exception if the string
is malformed? (odd number of delimiters, or opening/closing delims
don't match)
In the OP's case, he could get what he want's with a simple: l =
a.tokenize("'")
The point of this ramble not being that this is a how to solve the
OP's question, but wondering if it would be a good inclusion to the
language in general. Or there's actually a module which already does
it that I couldn't find and I'm an idiot...
Iain
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Re: String To List
On Mar 17, 6:56 am, Dan Bishop <[EMAIL PROTECTED]> wrote:
> On Mar 17, 1:15 am, Girish <[EMAIL PROTECTED]> wrote:
>
> > I have a string a = "['xyz', 'abc']".. I would like to convert it to a
> > list with elements 'xyz' and 'abc'. Is there any simple solution for
> > this??
> > Thanks for the help...
>
> eval(a) will do the job, but you have to be very careful about using
> that function. An alternative is
>
> [s.strip('\'"') for s in a.strip('[]').split(', ')]
This will fall over if xyz or abc include any of the characters your
stripping/splitting on (e.g if xyz is actually "To be or not to be,
that is the question"). Unless you can guarantee they won't, you'll
need to write (or rather use) a parser that understands the syntax.
Iain
--
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Re: the annoying, verbose self
On Nov 27, 12:03 pm, Duncan Booth <[EMAIL PROTECTED]> wrote: > Iain King <[EMAIL PROTECTED]> wrote: > > FTR, I won't be using this :) I do like this syntax though: > > > class Vector: > > def __init__(self, x, y, z): > > self.x = x > > self.y = y > > self.z = z > > def abs(self): > > using self: > > return math.sqrt(.x*.x + .y*.y + .z*.z) > > It is a bit verbose though. This variant is shorter on my system[*]: > > class Vector: > def __init__(self, x, y, z): > self.x = x > self.y = y > self.z = z > def abs(self): > return math.sqrt(self.x*self.x + self.y*self.y + self.z*self.z) > > [*] Windows, they are the same length on Linux. > > :) Yeah, in this example. Another would be using NetworkConnection: .address = "127.0.0.1" .port = "8080" .connect() using .connection while .read(): do something .disconnect() I doubt anything like this will take though, since you can write similar code with 'with' and assigning a long name to a short one. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: the annoying, verbose self
On Nov 27, 9:20 am, Roy Smith <[EMAIL PROTECTED]> wrote:
> In article <[EMAIL PROTECTED]>,
> Bruno Desthuilliers <[EMAIL PROTECTED]>
>
>
>
> wrote:
> > Steven D'Aprano a écrit :
> > > On Mon, 26 Nov 2007 21:48:36 +0100, Ton van Vliet wrote:
>
> > >> On Mon, 26 Nov 2007 20:14:50 +0100, Bruno Desthuilliers
> > >> <[EMAIL PROTECTED]> wrote:
>
> > However, I was more thinking in terms of attributes only
> > >>> Too bad : in Python, everything's an object, so 'methods' are attributes
> > >>> too.
> > >> Right, but I'm sure *you* know a way to distinguish between them
>
> > Yes : reading the doc. But that's something the compiler will have hard
> > time doing.
>
> > >> (I'm
> > >> just a beginner ;-)
>
> > > All methods are attributes. Not all attributes are methods. The usual way
> > > to see if something is a method is to try calling it and see what
> > > happens, but if you want a less informal test, try type():
>
> > type(''.join)
> > >
> > type(Foo().foo) # with the obvious definition of Foo
> > >
>
> > Fine. Now since Python let you define your own callable types and your
> > own descriptors, you can as well have an attribute that behave just like
> > a method without being an instance of any of the method types - so the
> > above test defeats duck typing. And since you can have callable
> > attributes that are definitively not methods, you can't rely on the fact
> > that an attribute is callable neither.
>
> If you want to have a little fun:
>
> class peverse:
> def __call__(self):
> raise AttributeError ("peverse instance has no __call__ method")
>
> x = peverse()
> x()
Horrific cluge:
--
def noself(func):
def t(*args, **kwargs):
self = args[0]
g = globals()
delete = []
for varname in dir(self):
if not varname.startswith("__") and varname not in g:
g[varname] = self.__getattribute__(varname)
delete.append(varname)
func(*args, **kwargs)
for varname in delete:
del(g[varname])
return t
class Test(object):
x = 1
@noself
def test(self):
print x
>>> foo = Test()
>>> foo.test()
1
--
FTR, I won't be using this :) I do like this syntax though:
class Vector:
def __init__(self, x, y, z):
self.x = x
self.y = y
self.z = z
def abs(self):
using self:
return math.sqrt(.x*.x + .y*.y + .z*.z)
Iain
--
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Re: Best way to generate alternate toggling values in a loop?
On Oct 18, 2:29 am, Grant Edwards <[EMAIL PROTECTED]> wrote: > On 2007-10-17, Debajit Adhikary <[EMAIL PROTECTED]> wrote: > > > # Start of Code > > > def evenOdd(): > > values = ["Even", "Odd"] > > state = 0 > > while True: > > yield values[state] > > state = (state + 1) % 2 > > I'd replace the last line with > > state ^= 1 > > to save a couple instructions, but I spend too much time > working with micoroprocessors running on clocks measured in the > KHz. > > There are probably other more Pythonic ways... > I always use: state = 1 - state for toggles. I doubt it's much more pythonic though :) Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Difference between two times (working ugly code, needs polish)
On Sep 12, 1:31 am, "Shawn Milochik" <[EMAIL PROTECTED]> wrote: > > I suppose really oneDay should be a global (i.e. outside the function > > definition). Apart from that it would be hard to improve on: obvious, > > easy to read, in short - pythonic. > > > Are you concerned about daylight savings? That could certainly introduce > > a whole new level of complexity into the problem. Let's hope not ... > > I'm not concerned with DST; this is a script which checks my Ebay > auctions (I have some things for sale), and sends me e-mail whenever > someone bids. It's run by cron every half hour -- it keeps me from > compulsively checking my auctions. ^_^ > > In any case, DST isn't an issue because the same machine generates > both timestamps, and all I use it for is to stop displaying auctions > after they are 10 days old, so I don't get all my old crap filling up > the alert e-mail or skewing the total dollar amount for all active > auctions. > > Thanks. > Shawn Just to be picky - your function returns the number of days between two dates, but it's called isOld, which looks like it should return a boolean. i.e. it looks like it would be used as: if not isOld(auctionDate, currentTime): checkForBid() rather than how I assume it is used: if isOld(auctionDate, currentTime) <= 10: checkForBid() I'd call it daysDiff or something similar, or make it more specific so that it works like the first block of code above: ONEDAY = 60*60*24 OLDNESS_THRESHOLD = 10 def isOld(lastUpdate, runTimeStamp): lastUpdate = time.mktime(time.strptime(lastUpdate, "%Y-%m-%d_%H: %M")) runTimeStamp = time.mktime(time.strptime(runTimeStamp, "%Y-%m-%d_ %H:%M")) return (runTimeStamp - lastUpdate) / ONEDAY >= OLDNESS_THRESHOLD if not isOld(auctionDate, currentTime): checkForBid() Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: wxPython and threads
On Jul 18, 3:41 am, Benjamin <[EMAIL PROTECTED]> wrote: > I'm writing a search engine in Python with wxPython as the GUI. I have > the actual searching preformed on a different thread from Gui thread. > It sends it's results through a Queue to the results ListCtrl which > adds a new item. This works fine or small searches, but when the > results number in the hundreds, the GUI is frozen for the duration of > the search. I suspect that so many search results are coming in that > the GUI thread is too busy updating lists to respond to events. I've > tried buffer the results so there's 20 results before they're sent to > the GUI thread and buffer them so the results are sent every .1 > seconds. Nothing helps. Any advice would be great. I do something similar - populating a bunch of comboboxes from data takes a long time so I run the generator for the comboboxes in another thread (and let the user use some textboxes in the mean time). A rough edit toward what you might be doing: import thread class Processor(object): def __init__(self): self.lock = thread.allocate_lock() self.alive = False self.keepalive = False def start(self): if not self.alive: self.alive = True self.keepalive = True thread.start_new_thread(self.Process, (None,)) def stop(self): self.keepalive = False def process(self, dummy=None): self.alive = False class SearchProcessor(Processor): def __init__(self, entries, lookfor, report): Processor.__init__(self) self.entries = entries self.lookfor = lookfor self.report = report def process(self, dummy=None): for entry in self.entries: if lookfor in entry: self.report(entry) if not self.keepalive: break self.report(None) self.alive = False results = [] def storeResult(result): if result != None: results.append(result) else: notifySomeMethod(results) sp = SearchProcessor(someListOfData, someTextToSearchFor, storeResult) sp.start() when the search is done it will call notifySomeMethod with the results. Meanwhile you could, for example, bind sp.stop() to a cancel button to stop the thread, or add a counter to the storeResult function and set a status bar to the total found, or whatever else you want to do. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: edit a torrent file with python
di0rz` wrote: > hi, > I am looking for a python script to edit .torrent files > if anybody know one thx Not sure exactly what you are looking for, but the original bittorrent client is written in Python, so you could grab a copy of it and check the code. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Is it possible to save a running program and reload next time ?
[EMAIL PROTECTED] wrote: > Hi, > > I have a program which will continue to run for several days. When it is > running, I can't do anything except waiting because it takes over most > of the CUP time. > > Is it possible that the program can save all running data to a file when > I want it to stop, and can reload the data and continue to run from > where it stops when the computer is free ? > > Regards, > > xiaojf Can't you just use time.sleep to put your program to, uh, sleep? For example, time.sleep(10) will effectively pause your program for ten seconds, making it use very few CPU cycles. I don't know what interface you have, but assuming you can pick up a button or a key press, you can ask for a length of time, or just put your code into a holding pattern: def pause(): paused = True while paused: time.sleep(1) if wake_up_key_pressed: paused = False or with a gui: paused = False def pause(): global paused paused = True while paused: time.sleep(1) def onWakeUpButton(): #bind this to button global paused paused = False Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: PIL cannot open TIFF image in Windows
Michele Petrazzo wrote: > Rob Williscroft wrote: > > > I downloaded some test images from: > > > > http://www.remotesensing.org/libtiff/images.html> > > > > I do the same and modified your code for try FreeImagePy and the results > are: > > ok: 41 error: 20 total: 61 > > Better than PIL, but a lot of problems with > > lower-rgb-planar- > 8 and flower-rgb-contig- > 8 > > IrfanView seem that can load all the images... > > > Rob. > > Bye, > Michele I've been working with tifs a lot, and I've yet to find a perfect python solution to them. The usual images to screw things up for me are jpeg encoded pages. Best solution I've found is a try/except fall through: try: open image with PIL except: try: open image with FreeImagePy except: try: open image with wxPython except: fail Right now my program to compile multipage tiffs no longer does any of the image work itself - it processes the index file, and then generates a batch file. The batch file is a lot of calls to irfanview /append. I've yet to find a tiff irfanview can't open. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking For mp3 ID Tag Module
Tim Daneliuk wrote: > Iñigo Serna wrote: > > On 8/18/06, Tim Daneliuk <[EMAIL PROTECTED]> wrote: > >> > try mutagen. > >> http://www.sacredchao.net/quodlibet/wiki/Development/Mutagen > >> > >> This module is more-or-less exactly what I needed. However, I am running > >> into problems when the filenames or ID tags have unicode characters in > >> them. > >> > >> Typically, I do something like: > >> > >> from mutagen.easyid3 import EasyID3 > >> > >> audio["title'] = Something based on the filename that has unicode > >> chars in it > >> > >> I then get this: > >> > >> UnicodeDecodeError: 'ascii' codec can't decode byte 0xfc in position > >> 56: ordinal not in range(128) > > > >> From the docs: > > """Mutagen has full Unicode support for all formats. When you assign > > text strings, we strongly recommend using Python unicode objects > > rather than str objects. If you use str objects, Mutagen will assume > > they are in UTF-8.""" > > > > So I suppose the value you try to assign as title is not unicode, > > check the encoding used in the file system. > > > > Iñigo > > I am trying to set the title based on the filename. The file is in a Win32 > NTFS filesystem, so it could have non-ASCII chars in it. What I am stumbling > on it how to coerce it into unicode. I have tried: > > name = filename.split() blah blah blah > audio["title"] = unicode(name) > > But I still get this error. I am not real up to speed on the whole unicode > end of things, so any kind suggestions would be most welcome. > > By the way, I believe the offending string contains a German umlaut, at least > in one > of the cases. > > To get the MP3's name, use os.path.basename (I'm guessing that's what your split() is for?) Looking at the mutagen tutorial, most of the tags are lists of unicode strings, so you might want to try audio["title"] = [unicode(name)], instead of audio["title"] = unicode(name). This might be your problem when reading the tags, too. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: The Semicolon Wars as a software industry and human condition
Xah Lee wrote: > Of interest: > > • The Semicolon Wars, by Brian Hayes. 2006. > http://www.americanscientist.org/template/AssetDetail/assetid/51982 > > in conjunction to this article, i recommend: > > • Software Needs Philosophers, by Steve Yegge, 2006 > http://xahlee.org/Periodic_dosage_dir/_p/software_phil.html > > • What Languages to Hate, Xah Lee, 2002 > http://xahlee.org/UnixResource_dir/writ/language_to_hate.html > > Xah > [EMAIL PROTECTED] > ∑ http://xahlee.org/ I'm confused - I thought Xah Lee loved Perl? Now he's bashing it? Huh? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: FOR LOOPS
OriginalBrownster wrote:
> I am using a class called UploadedFile.
> I want to create a for loop to itterate through the objects within file
> name
>
> class UploadedFile(SQLObject):
> filename = StringCol(alternateID=True)
> abspath = StringCol()
> uniqueid = IntCol()
>
> I'll show you a snippit of the code I am trying to use it in::
>
>
> zip= ["zip.txt"]
> file_path = [myfile.filename for myfile in
> UploadedFile.select(orderBy=UploadedFile.q.filename)]
>
> if kw:
> for filename in file_path:
> zip.append(filename)
> flash('Options selected'+ str(kw) + str(zip))
> else:
> pass
>
> When i run this the flash displays all the values for kw...however zip
> only shows up as "zip.txt" using the str function. Meaning that the FOR
> LOOP is not working correctly.
After your 'file_path =' line, try adding a 'print file_path', and see
if it's creating it correctly. Your for loop looks fine, assuming that
file_path is a list of filenames.
Iain
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Re: random shuffles
Dustan wrote: > Boris Borcic wrote: > > does > > > > x.sort(cmp = lambda x,y : cmp(random.random(),0.5)) > > > > pick a random shuffle of x with uniform distribution ? > > > > Intuitively, assuming list.sort() does a minimal number of comparisons to > > achieve the sort, I'd say the answer is yes. But I don't feel quite > > confortable > > with the intuition... can anyone think of a more solid argumentation ? > > Why not use the supplied shuffle method? > > random.shuffle(x) or check out this thread: http://groups.google.com/group/comp.lang.python/browse_thread/thread/766f4dcc92ff6545?tvc=2&q=shuffle Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: using names before they're defined
[EMAIL PROTECTED] wrote: > Iain, thanks - very helpful. > > Really I'm trying to write a simulation program that goes through a > number of objects that are linked to one another and does calculations > at each object. The calculations might be backwards or fowards (i.e. > starting at the supply or demand ends of the system and then working > through the objects). And also, I might have multiple objects linked to > a single object (upstream or downstream) - e.g. compressor -- multiple > combusters - turbine > > I like your idea of using something like a setStreams method to > establish the linking. The streams do reflect each other, although > having many-to-one and vice versa will complicate that. I have not > quite got my head around having multiple links. In C++ I would be > thinking about something like a linked-list but I'm not sure that's the > right approach here. > > Dave You don't need linked-lists : python has a list type built in. Example: class Component(): upstream = [] downstream = [] def addUpstream(self, c): self.upstream.append(c) if not self in c.downstream: c.addDownstream(self) def addDownstream(self, c): self.downstream.append(c) if not self in c.upstream: c.addUpstream(self) def remUpstream(self, c): c.downstream.remove(self) self.upstream.remove(c) def remDownstream(self, c): c.upstream.remove(self) self.downstream.remove(c) def cascadeDownTest(self): print self # this could run forever if you connect components in a circle: for c in self.downstream: c.cascadeDownTest() Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: using names before they're defined
[EMAIL PROTECTED] wrote: > I have a problem. I'm writing a simulation program with a number of > mechanical components represented as objects. When I create instances > of objects, I need to reference (link) each object to the objects > upstream and downstream of it, i.e. > > supply = supply() > compressor = compressor(downstream=combustor, upstream=supply) > combuster = combuster(downstream=turbine, upstream=compressor) > etc. > > the problem with this is that I reference 'combustor' before is it > created. If I swap the 2nd and 3rd lines I get the same problem > (compressor is referenced before creation). > > > aargh!!! any ideas on getting around this? > > Dave At the top of your code you could put: supply = None compressor = None combuster = None turbine = None It might be better, though, to arrange your code like: supply = Supply() compressor = Compressor() combuster = Combuster() turbine = Turbine() compressor.setStreams(down=combuster, up=supply) combuster.setStreams(down=turbine, up=compressor) Do the streams reflect each other? That is, if supply.down is compressor, is compressor.up supply? In that case you probably want to do something like: class Component(): upstream = None downstream = None def setUpstream(self, c): self.upstream = c if c.downstream != self: c.setDownstream(self) def setDownstream(self, c): self.downstream = c if c.upstream != self: c.setUpstream(self) class Supply(Component): pass etc. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: question about what lamda does
Steve Holden wrote: > tac-tics wrote: > > [EMAIL PROTECTED] wrote: > > > >>Hey there, > >>i have been learning python for the past few months, but i can seem to > >>get what exactly a lamda is for. What would i use a lamda for that i > >>could not or would not use a def for ? Is there a notable difference ? > >>I only ask because i see it in code samples on the internet and in > >>books. > > > > > > Lambda is just as powerful as a function, but totally useless =-P > > > > Lambda used to be handy before the introduction of list comprehensions. > > Now, though, there primary use is obfuscating your code. > > > I do wish you could hold yourself back and stop muddying the waters. > Lambdas and list comprehensions have little or nothing to do with each > other. Unless you know something I don't ... > I think he meant that lambda's main use before was inside map and filter; as stated earlier in the thread, lambda's main use was for passing simple functions as arguments, and of these map and filter must have made up a majority (and then I'd guess TKinter would be next). List comprehensions replace map and filter, so... I wouldn't put it as explosively as he has, but I find a lambda less clear than a def too. Iain > regards > Steve > -- > Steve Holden +44 150 684 7255 +1 800 494 3119 > Holden Web LLC/Ltd http://www.holdenweb.com > Skype: holdenweb http://holdenweb.blogspot.com > Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
Re: Full splitting of a file's pathname
tac-tics wrote: > I know about os.path.split(), but Is there any standard function for > "fully" splitting a file's pathname? A function that is the opposite of > the os.path.join() function? For example: > > >>> ret = myster_function(./foo/bar/moo/lar/myfile.txt) > >>> print ret > ['.', 'foo', 'bar', 'moo', 'lar', 'myfile.txt'] > > In the meanwhile, I'll do this by hand. I'm just curious if there is a > standard way to do this. Simple function using os.path.split (so it should be fairly compatible): def split(path): h,t = os.path.split(path) if h == path: return [h] else: return split(h) + [t] You could throw in os.path.splitdrive and os.path.splitunc, if you wanted to be really complete. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: List Manipulation
Mike Kent wrote:
> Roman wrote:
> > Thanks for your help
> >
> > My intention is to create matrix based on parsed csv file. So, I would
> > like to have a list of columns (which are also lists).
> >
> > I have made the following changes and it still doesn't work.
> >
> >
> > cnt = 0
> > p=[[], [], [], [], [], [], [], [], [], [], []]
> > reader = csv.reader(file("f:\webserver\inp.txt"), dialect="excel",
> > quotechar="'", delimiter='\t')
> > for line in reader:
> > if cnt > 6:
> >break
> > j = 0
> > for col in line:
> >p[j].append(col)
> >j=j+1
> > cnt = cnt + 1
> >
> > print p
>
> p[j] does not give you a reference to an element inside p. It gives
> you a new sublist containing one element from p. You then append a
> column to that sublist. Then, since you do nothing more with that
> sublist, YOU THROW IT AWAY.
>
> Try doing:
>
> p[j] = p[j].append(col)
>
No, this doesn't work. append is an in-place operation, and you'll end
up setting p[j] to it's return, which is None.
Iain
--
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Re: List Manipulation
Roman wrote:
> I would appreciate it if somebody could tell me where I went wrong in
> the following snipet:
>
> When I run I get no result
>
> cnt = 0
> p=[]
> reader = csv.reader(file("f:\webserver\inp.txt"), dialect="excel",
> quotechar="'", delimiter='\t')
> for line in reader:
> if cnt > 6:
>break
> for col in line:
>p[:0].append(str(col))
What are you trying to do here? p[:0] returns a new list, of all the
elements in p up to element 0 (which is of course the empty list),
which is then appended to, but is not stored anywhere. If you want to
insert str(col) then use p.insert
Iain
--
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Re: conecting with a MsAcces DB by dao
luis wrote:
> Iain King ha escrito:
>
> > luis wrote:
> > > Iain King ha escrito:
> > >
> > > > luis wrote:
> > > > > while not rs.EOF:
> > > > > id=rs.Fields(colName.Value) #colName, valid column name
> > > > > ...
> > > > > rs.MoveNext()
> > > > > rs.Close()
> > > > > conn.Close()
> > > >
> > > > I don't know if it's the problem your asking about, but your
> > > > rs.MoveNext() should be inside the while loop, no?
> > > Yes, is inside
> > > >
> >
> > You mean, it is inside the while loop in your code, but you made a
> > mistake copying it into your post? In the code you posted it is not
> > inside the while loop - it would have to be indented one more level for
> > that.
> >
> > Iain
>
> this is te correct identation
>
> def append_from_Access(self):
>try:
> import ...
> conn = win32com.client.Dispatch(r'ADODB.Connection')
> DSN = "PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA
> SOURCE=C:/Afile.mdb;"
> conn.Open(DSN)
>except Exception, inst:
>...
>try:
> sql_statement='SELECT * FROM Mytable'
> rs = win32com.client.Dispatch(r'ADODB.Recordset')
> rs.Open(sql_statement, conn, 1, 3)
> while not rs.EOF:
> id=rs.Fields(colName.Value) #colName, valid column name
> ...
> rs.MoveNext()
> rs.Close()
> conn.Close()
>
> except Exception, inst:
> ...
>
> I think my problem must be with ado and dao.
> Now I have run makepy utility and select Microsoft ActiveX Data Objects
> 2.5 Library, perhaps I must also select Microsoft DAO3.5 Object Library
> and write
> win32com.client.Dispatch("DAO.DBEngine.35") for Access 97 or
> win32com.client.Dispatch(r'ADODB.Connection') for Acess 2000
> Do you know is it possible ?
> luis
Well, without being able to test on your system I don't think I can
give you any real advice. This is the module I use to interface with
Access:
Access.py
---
import win32com.client
from win32com.client import constants
def isWriteable(field):
"""Is given Field writeable?"""
return field.Attributes & 4
class Access(object):
def __init__(self, filename, password=""):
self._filename = filename
self._connection = win32com.client.Dispatch(r'ADODB.Connection')
if password:
self._DSN = 'PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA
SOURCE=%s;Jet
OLEDB:Database Password=%s;' % (filename, password)
else:
self._DSN = 'PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA
SOURCE=%s;' %
(filename)
def Query(self, query):
self._connection.Open(self._DSN)
rs = win32com.client.Dispatch(r'ADODB.Recordset')
rs.Open(query, self._connection, 1, 3)
fields = []
for x in xrange(rs.Fields.Count):
fields.append(rs.Fields(x).Name)
if rs.EOF:
data = []
else:
data = rs.GetRows()
rs.Close()
self._connection.Close()
return fields, data
def Add(self, table, records):
"""Adds records to table."""
self._connection.Open(self._DSN)
rs = win32com.client.Dispatch(r'ADODB.Recordset')
rs.Open(table, self._connection, 1, 3)
unwriteables = []
for record in records:
rs.AddNew()
unwriteable = []
for i in xrange(len(record)):
if isWriteable(rs.Fields(i)):
rs.Fields(i).Value = record[i]
else:
unwriteable.append(rs.Fields(i).Value)
unwriteables.append(unwriteable)
rs.Update()
rs.Close()
self._connection.Close()
return unwriteables
def Update(self, query, function):
"""Updates all records found in query with function(record)"""
self._connection.Open(self._DSN)
rs = win32com.client.Dispatch(r'ADODB.Recordset')
rs.Open(query, self._connection, 1, 3)
columns = rs.Fields.
Re: conecting with a MsAcces DB by dao
luis wrote: > Iain King ha escrito: > > > luis wrote: > > > while not rs.EOF: > > > id=rs.Fields(colName.Value) #colName, valid column name > > > ... > > > rs.MoveNext() > > > rs.Close() > > > conn.Close() > > > > I don't know if it's the problem your asking about, but your > > rs.MoveNext() should be inside the while loop, no? > Yes, is inside > > You mean, it is inside the while loop in your code, but you made a mistake copying it into your post? In the code you posted it is not inside the while loop - it would have to be indented one more level for that. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: conecting with a MsAcces DB by dao
luis wrote: > Hi > I'm using activestate python 2.4 on win xp 2 ed. and Ms Access 2002 > (reading first http://starship.python.net/crew/bwilk/access.html) > I have writed the following code > > def append_from_Access(self): >try: > import ... > conn = win32com.client.Dispatch(r'ADODB.Connection') > DSN = "PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA > SOURCE=C:/Afile.mdb;" > conn.Open(DSN) >except Exception, inst: >... >try: > sql_statement='SELECT * FROM Mytable' > rs = win32com.client.Dispatch(r'ADODB.Recordset') > rs.Open(sql_statement, conn, 1, 3) > while not rs.EOF: > id=rs.Fields(colName.Value) #colName, valid column name > ... > rs.MoveNext() > rs.Close() > conn.Close() > > except Exception, inst: > ... > > I'm using it for reading tables or queries in a mdb file. > With some mdb it works fine and return a no empty recordset, but with > others mdb files, the recordsets are void (opening the tables or > recorsets with Ms Access are not void). > Some help is welcome, > Thanks in advance > Luis I don't know if it's the problem your asking about, but your rs.MoveNext() should be inside the while loop, no? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: String Question
Tim Roberts wrote:
> "Iain King" <[EMAIL PROTECTED]> wrote:
> >
> >You probably want:
> >
> >s.sendto('\xff'*6 + ('\x%s\x%s\x%s\x%s\x%s\x%s' % (str01, str02, str03,
> > sttr04, str05, str06))*16, ('192.168.1.255', 80))
>
> You probably should TRY suggestions before you post them. That will get an
> "invalid \x escape". \x must be followed by exactly two hex digits. You
> can't build up an escape sequence like this.
> --
> - Tim Roberts, [EMAIL PROTECTED]
> Providenza & Boekelheide, Inc.
You're right. I'd foolishly assumed that \x was just another character
code, like \t or \n. Apologies.
Iain
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Re: String Question
[EMAIL PROTECTED] wrote:
> mac_string = '001485e55503' (This is the mac address of a computer.)
>
> I am using wake on LAN python script to start computer remote.It uses
> format like this
>
> s.sendto('\xff'*6 + '\x00\x014\x85\xe5\x55\x03'*16, ('192.168.1.255',
> 80))
>
> where '\x00\x14\x85\xe5\x55\x03' is the MAC address to be used.
>
>
> What I do is break the string into 6 parts like this,
>
> str01=mac_string[0:2]
> str02=mac_string[2:4]
> str03=mac_string[4:6]
> str04=mac_string[6:8]
> str05=mac_string[8:10]
> str06=mac_string[10:12]
>
> and if I use it like this
>
> s.sendto('\xff'*6 + '\xstr01\xstr02\xstr03\xstr04\xstr05\xstr06'*16,
> ('192.168.1.255', 80))
> I get an error
>
>
> I also tried like this
> s.sendto('\xff'*6 + 'mac_string'*16, ('192.168.1.255', 80))
>
> Thiis also didnt work.
>
>
> Since the MAC adddress are hexadecimal, how should I go about it here.
>
> Please help, every help is appreciated. Thanks
See http://docs.python.org/lib/typesseq-strings.html
You probably want:
s.sendto('\xff'*6 + ('\x%s\x%s\x%s\x%s\x%s\x%s' % (str01, str02, str03,
sttr04, str05, str06))*16, ('192.168.1.255', 80))
Iain
--
http://mail.python.org/mailman/listinfo/python-list
Re: Feed wxComboBox with dictionary/hash
Roland Rickborn wrote:
> Hi folks,
>
> I am relatively new to Python. Although I read a lot of howtos,
> introductions and wikis, I am still having trouble ;-)
>
> My querstion:
> As the subject says, I'd like to feed a wx.ComboBox with a
> dictionary/hash. According to the posting of Stano Paska ("wxComboBox
> <> combobox", 20 Jul. 2004), there seems to be a way to do this:
>
> > You must use something like
> > combo.Append('aaa', 'a')
> > combo.Append('bbb', 'b')
> > ...
>
> My problem is:
> my data has thousands of entries. Therefore, I'd like to feed the
> combobox with a dictionary (which itself is fed by a database query).
>
> My first question:
> how can a wx.ComboBox be fed by a dictionary?
>
> For further help, Stano says:
>
> > read manual for more details...
>
> Ok, I'd like to. But which one?
> I was reading http://www.wxpython.org/docs/api/wx.ComboBox-class.html
> and didn't even find the above mentioned append method :-(
>
> TIA,
> Roland R.
wxComboBox inherits from wxControlWithItems (as does wx.ListBox, and
other controls which hold lists). See:
http://wxwidgets.org/manuals/2.6.3/wx_wxcontrolwithitems.html#wxcontrolwithitems
Iain
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Re: .py and running in Windows:
Andrew Gwozdziewycz wrote: > You'll have better results posting this to it's own thread. > He certainly should have, but since I've read it here anyway: > On Jun 13, 2006, at 9:29 AM, Michael Yanowitz wrote: > > > Hello: > > > > Presently in my Windows 2000 system, when I double-click on a > > .py file (open it) it automatically runs it in Python. I would > > like to change that behavour. That is fine for .pyc file, but > > for .py files, I would either like to have it run in Python but > > return to the Python shell prompt when finished rather than > > exit the shell. How do I do that? > > Or would it cause a problem (so that Python no longer works) if > > I change the default .py extension to open in an editor rather > > than execute it if I open it? > > In an explorer window, go to Tools->Folder Options Go to the File Types tab, find the PY extension, then click on Advanced* Select the 'open' action, and click Edit... change the 'Application used to perform action', inserting a '-i' between the exe and the first parameter. For example, I changed mine to: "C:\Python\python.exe" -i "%1" %* The exact line will depend on where your python.exe is. OK all the dialogs you've opened, then double click a .py file to test it. *I'm using WinXP, so the exact name of some of the buttons may be different for you. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: pyqt show wizard
David Boddie wrote: > Summary of the usual mess made by the Google Groups web interface: > > > I suspect that you really want to call w.exec_loop() instead, since > this will only return control to the method after the user has finished > interacting with the wizard. > > > Take a look at the QWizard documentation for more information: > > > http://doc.trolltech.com/3.3/qwizard.html > > > David test -- http://mail.python.org/mailman/listinfo/python-list
Bug in list comprehensions?
I was playing with list comprehensions, to try and work out how doubled up versions work (like this one from another thread: [i for i in range(9) for j in range(i)]). I think I've figured that out, but I found something strange along the way: >>> alpha = ["one", "two", "three"] >>> beta = ["A", "B", "C"] >>> [x for x in alpha for y in beta] ['one', 'one', 'one', 'two', 'two', 'two', 'three', 'three', 'three'] >>> [x for x in y for y in beta] ['C', 'C', 'C'] >>> beta = [alpha, alpha, alpha] >>> beta [['one', 'two', 'three'], ['one', 'two', 'three'], ['one', 'two', 'three']] >>> [x for x in y for y in beta] ['C', 'C', 'C'] >>> [y for y in beta] [['one', 'two', 'three'], ['one', 'two', 'three'], ['one', 'two', 'three']] >>> [x for x in y for y in beta] ['one', 'one', 'one', 'two', 'two', 'two', 'three', 'three', 'three'] Shoudn't both lines '[x for x in y for y in beta]' produce the same list? I'm guessing I'm the one confused here... but I'm confused! What's going on? Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Large Dictionaries
Lawrence D'Oliveiro wrote: > In article <[EMAIL PROTECTED]>, > Scott David Daniels <[EMAIL PROTECTED]> wrote: > > >For example, time timsort (Python's internal sort) on pre-sorted > >data; you'll find it is handled faster than random data. > > But isn't that how a reasonable sorting algorithm should behave? Less > work to do if the data is already sorted? An already sorted list can be pathological for Quicksort, depending on how you code it. Iain -- http://mail.python.org/mailman/listinfo/python-list
Re: Trying to get FreeImagePy to work.
Michele Petrazzo wrote: > Iain King wrote: > >> I'll try out FIPY's resizing tomorrow too. OTOH, I have functions > >> to convert between PIL and wxPython, and functions to convert > >> betweem PIL and FIPY, but I don't see a function to convert FIPY to > >> wxPython? > >> > > > > Image at: http://www.snakebomb.com/misc/example.tif > > > > Iain > > > > Yes it's min-is-white:: > > michele:~$ tiffinfo example.tif > TIFFReadDirectory: Warning, example.tif: unknown field with tag 37680 > (0x9330) encountered. > TIFF Directory at offset 0x1520 (5408) >Subfile Type: (0 = 0x0) >Image Width: 1696 Image Length: 1162 >Resolution: 200, 200 pixels/inch >Bits/Sample: 1 >Compression Scheme: CCITT Group 4 >Photometric Interpretation: min-is-white# <-- >FillOrder: msb-to-lsb >Samples/Pixel: 1 >Rows/Strip: 1162 >Planar Configuration: single image plane >ImageDescription: DS > michele:~$ > > So you *need* to invert it to work correctly with PIL! > > P.s. Added the convertToWx function, that return a wx.Image, to the > Image class. > > Michele Most excellent! Iain -- http://mail.python.org/mailman/listinfo/python-list
