Re: sum up numbers in a list
L=['10','15','20']
sum(int(x) for x in L)
45
or
sum(map(int,L))
45
sharon kim wrote:
hi all,
i have a list, for example;
L=[]
L.append('10')
L.append('15')
L.append('20')
len(L)
3
print L
['10', '15', '20']
is there a way to sum up all the numbers in a list? the number of
objects in the list is vary, around 50 to 60. all objects are 1 to 3
digit positive numbers.
all i can think of is check the length of the list (in the above
example, 3), then L[0]+L[1]+L[2] ..
is there a better way to do the job? thanks.
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Re: Books for learning how to write big programs
duli wrote: Hi: I would like recommendations for books (in any language, not necessarily C++, C, python) which have walkthroughs for developing a big software project ? So starting from inception, problem definition, design, coding and final delivery on a single theme or application. Most of the code I have written and books that I have read deal with toy programs and I am looking for something a bit more comprehensive. For example, maybe a complete compiler written in C++ for some language, or a complete web server or implementing .net libraries in some language (just a few examples of the scale of things I am interested in learning). Thanks! Duli. -- http://mail.python.org/mailman/listinfo/python-list Dreaming in Code www.dreamingincode.com may fit part of this description. While it isn't exactly what you desire, it is a good read on the difficulty in creating excellent software. -- http://mail.python.org/mailman/listinfo/python-list
Re: Problems with psycopg2
David Anderson wrote:
The thing is this query works fine on the console through psql, but not
in my code? can anyone explain me why?
On Thu, May 1, 2008 at 9:31 PM, David Anderson [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED] wrote:
Hi all
I have this function:
def checkName(self, name):
cur = self.conn.cursor()
sql = SELECT * from patient WHERE fn_pat = ' + name + '
cur.execute(sql)
rows = cur.fetchall()
if rows == []:
self.insert()
It seems to work fine, But I'm getting this exception:
psycopg2.ProgrammingError: current transaction is aborted, commands
ignored until end of transaction block
at: cur.execute(sql)
What's the problem?
thx
ps: fn_pat is the column of the db, name is the string passed in the
function parameter
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Does `name` happen to have an apostrophe in it? You may want to look at
using bind variables.
cur.execute(SELECT * from patient WHERE fn_pat=%(name)s,
{'name': name})
http://wiki.python.org/moin/DbApiCheatSheet
http://mail.python.org/pipermail/python-list/2005-March/314154.html
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keyword 'in' not returning a bool?
Try this
sample = {'t':True, 'f':False}
't' in sample
True
type('t' in sample)
type 'bool'
't' in sample == True
False
Why is this? Now try
bool('t' in sample) == True
True
Can someone explain what is going on?
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Re: Cheat sheet
Riccardo T. wrote: I wrote a little cheat sheet for this wonderful language, but because of my still little experience with it, I would like to have a feedback Could you have a look at it and tell me what do you think about, please? http://greyfox.imente.org/index.php?id=73 -- GreyFox On the svg version, as viewed on firefox, the sections Simple statements, Definations and Comments; there appears to be a problem with text wrapping. -- http://mail.python.org/mailman/listinfo/python-list
Overriding member methods in __init__
Given a condition at the time a class is instantiated, I want to change
how __call__ is used. From the example below, self.no is using self.yes
but self.__call__ is not. Can someone please explain why?
EXAMPLE:
class YesNo(object):
def __init__(self, which):
self.no = self.yes
self.__call__ = self.yes
def yes(self, val):
print 'Yes', val
def no(self, val):
print 'No', val
def __call__(self, val):
raise NotImplementedError()
y = YesNo(True)
y.yes('hello')
Yes hello
y.no('hello')
Yes hello
y('hello')
Traceback
Not ImplementedError
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Re: Overriding member methods in __init__
Bruno Desthuilliers wrote: c james a écrit : Given a condition at the time a class is instantiated, I want to change how __call__ is used. From the example below, self.no is using self.yes but self.__call__ is not. Can someone please explain why? IIRC, you can't override __magic__ methods on a per-instance basis. This should do the trick: class YesNo(object): def __init__(self, which): self.which = which def __call__(self, val): return (self.no, self.yes)[self.which](val) def yes(self, val): print 'Yes', val def no(self, val): print 'No', val Thanks, I was trying to eliminate another level of indirection with a test at each invocation of __call__ -- http://mail.python.org/mailman/listinfo/python-list
Re: Overriding member methods in __init__
Arnaud Delobelle wrote: Why not simply do: class YesNo(object): def __init__(self, which): self.yesno = which and self.yes or self.no def yes(self, val): print 'Yes', val def no(self, val): print 'No', val def __call__(self, val): self.yesno(val) I don't know which is fastest but I don't think there would be much difference. -- Arnaud This is more in the spirit of what I was trying to accomplish. Originally, I was unaware the __call__ could not be assigned a different method. -- http://mail.python.org/mailman/listinfo/python-list
Re: appending into a list
Beema shafreen wrote: 2721520 2721569A_16_P21360235199-49 2721768 2721821A_16_P03641971139-53 2721960 2722004A_16_P21360237312-44 I need to append the column D and E into a list: in such a way that the list should have [D,E,D,E,D,E] How do i do it. regards shafreen Without a header, you could use something like data = [x.split()[-2:] for x in open(filename).readlines()] With header f = open(filename) f.readline() data = [x.split()[-2:] for x in f.readlines()] -- http://mail.python.org/mailman/listinfo/python-list
Re: Pure Python equivalent of unix file command?
Take a look at http://www.demonseed.net/~jp/code/magic.py W3 wrote: Hi all, Just a quick one... Is there such a thing? Thanks, /Walter -- http://mail.python.org/mailman/listinfo/python-list
Re: multi threaded SimpleXMLRPCServer
I use a variation of the following. Clean and straight forward. http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/425043 Vyacheslav Maslov wrote: Hi, all! I need multi threaded version of SimpleXMLRPCServer. Does python library already have implementation of this one? Or i need to implement multi threading by myself? Which way is the simpliest? -- http://mail.python.org/mailman/listinfo/python-list
Re: Plugin architecture - how to do?
Take a look at Trac. This might give you some ideas. http://trac.edgewall.org/wiki/TracDev/ComponentArchitecture -- http://mail.python.org/mailman/listinfo/python-list
Re: SimpleXMLRPCServer - client address
Jan Danielsson wrote:
Hello all,
I writing an application based on the SimpleXMLRPCServer class. I
would like to know the IP address of the client performing the RPC. Is
that possible, without having to abandon the SimpleXMLRPCServer class?
I did this a long time ago so it's not likely the best solution.
class RPCServer(SimpleXMLRPCServer):
def _dispatch(self, method, params):
Extend dispatch, adding client info to some parameters.
if method in ({my list of methods I needed client address}):
return SimpleXMLRPCServer._dispatch(self, method,
params+(self.client_address,))
return SimpleXMLRPCServer._dispatch(self, method, params);
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Re: Controlling kwrite by dcop
On Sunday 08 May 2005 13:41, [EMAIL PROTECTED] wrote: As you can see you can interact with kwrite from dcop. Unfortunately I don't have this module in my Python (2.3) nor I have been able to find it. It's normally installed seperately from the main kde libraries - on gentoo it's a package called dcoppython, that might help you in your search if you're on a different distro. james. pgp55bUjWf3dA.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: large dictionary creation takes a LOT of time.
On Friday 29 April 2005 11:53, Ville Vainio wrote: Kent == Kent Johnson [EMAIL PROTECTED] writes: Kent if frequency.has_key(word): Kent frequency[word] += 1 Kent else: Kent frequency[word] = 1 This is a good place to use 'get' method of dict: frequency[word] = frequency.get(word,0) + 1 try/except might be fastest of all: http://gumuz.looze.net/wordpress/index.php/archives/2005/04/28/python-dictionary-speed-optimisation/ pgpyyTIumZQjr.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Multiple tuples for one for statement
On Monday 25 April 2005 04:20, James Stroud wrote: for a,b,c in zip(tup1, tup2, tup3): print a print b print c or just: for a,b,c in (tup1, tup2, tup3): print a print b print c pgpJ0RNTnCUA3.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Multiple tuples for one for statement
On Monday 25 April 2005 14:34, Ivan Van Laningham wrote: Hi All-- R. C. James Harlow wrote: or just: for a,b,c in (tup1, tup2, tup3): print a print b print c And this works in Python version??? Ah, reading the replies to the original post, this works but doesn't give the result that the original poster wanted. pgpottbqbjtRP.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Do I need a nested lambda to do this?
On Tuesday 26 April 2005 00:34, raoul wrote: I can't figure this one out. Trying to be unnecessarily functional I suspect. With list comprehensions: Python 2.3.4 (#1, Mar 26 2005, 20:54:10) [GCC 3.3.4 20040623 (Gentoo Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)] on linux2 Type help, copyright, credits or license for more information. vals = [1.000,2.344,4.2342] tabs = [((0,1),(0,3),(0,4)), ...((2,2),(3,0),(3,9)), ...((3,4),(6,3),(7,1))] [(tuple([(vals[index],subtab[1]) for subtab in tab])) for index,tab in enumerate(tabs)] [((1.0, 1), (1.0, 3), (1.0, 4)), ((2.3439, 2), (2.3439, 0), (2.3439, 9)), ((4.23420004, 4), (4.23420004, 3), (4.23420004, 1))] -- http://mail.python.org/mailman/listinfo/python-list
Re: Variables
On Sunday 24 April 2005 03:20, Richard Blackwood wrote: To All: Folks, I need your help. I have a friend who claims that if I write: foo = 5 then foo is NOT a variable, necessarily. This is a really amusingly recursive discussion. Your friend has a piece of knowledge, what a variable is and is not. He uses the word variable to refer to this piece of knowledge. Now, if in some parallel universe people used the word hairbrush to refer to this bit of knowledge, that wouldn't stop his argument having validity if he travelled to that universe - if it would then it's already invalidated, as there are more people in *this* universe who use the word variable to refer to foo than there are who insist that it's not correct, by a significant proportion. So by corollary your friend has already argued that one can use many different words to correctly refer to the same concept. I think your friend would also find it hard to disagree that a single word can have multiple meanings, like the example given of Domain in maths. I think he would have a similarly tough time saying that these words with multiple meanings were only allowable in maths, not in english or the offshoots of maths like programming. So there's no reason why the concept of what you call a variable and what he calls a variable shouldn't be different. In summary, the words he uses to describe variables are constants, but point at variables, which are different than the constants you use to describe variables, which point at variables, and vary from the variables that his variables point at. And if that last sentence doesn't convince him of the futility of trying to use natual language to communicate precise concepts, nothing will. pgp4lqQYa6ygj.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Parsing data from URL
On Monday 25 April 2005 01:24, Harlin Seritt wrote: dat = urllib.urlopen(url, 'r').read() Drop the 'r' - urlopen is posting the 'r' to the server, instead of doing what you mean, opening the file read-only. pgpmZ2zcMs1bO.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
On Thursday 21 April 2005 17:42, Maxim Kasimov wrote: Have you tried the triple quote comment technique? how do use this here: Simple. sql = ''' some long query ''' Change this to: sql = some long query since you shouldn't be using multiple quoting styles in one module, any more than you should be using multiple casing styles. Then just put single quotes around the place where you want to comment. Not hard, is it? james. pgpEOkrYjHYZq.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Supercomputer and encryption and compression @ rate of 96%
On Thursday 14 April 2005 10:27, [EMAIL PROTECTED] wrote: Supercomputer and encryption and compression @ rate of 96% snip Dear Sir or Madam, I have received notification that you posted a compression algorithm on the newsgroup comp.lang.python on or about 10:27:26 on the 04/14/2005. I am writing to you to inform you that the algorithm published infringes my zero-bit compression algorithm, US Pat No. 13375P33K, which details the transmission of information using no bandwidth to achieve a 100% compression. Please immediately follow up with a retraction of rights to this algorithm or you will hear from my solicitor, Mr J. Peasbody. Yours in law, James Harlow. -- http://mail.python.org/mailman/listinfo/python-list
Re: Piping data into script under Win32
On Saturday 16 April 2005 03:11, runes wrote: I trying to figure out a way to make a python script accept data output from another process under Windows XP, but I fail miserably. I have a vague memory having read this is not possible with Python under Windows... C:\ type countlines.py | python countlines.py Counted 3 lines. Are you definitely doing this and not: C:\ type countlines.py | countlines.py That will give you the error you're seeing. The example you posted works for me. pgpG1kLcMgQ3U.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Piping data into script under Win32
On Saturday 16 April 2005 03:43, runes wrote: type countlines.py | python countlines.py = Success type countlines.py | countlines.py = Failure Why doesn't the latter work? Don't quote me on this, but I think it's because invoking countlines.py involves running some sort of wrapper that discards its stdin and stdout. If anyone has a more authorative answer, I'd like to know, because this caught me out too. james. pgp0UPpjLSwGF.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Supercomputer and encryption and compression @ rate of 96%
On Thursday 14 April 2005 22:18, Tiziano Bettio wrote: Actually your script doesn't work on my python distribution... Works fine here - did you decompress the first bit of the python executable? You have to do that before Fredrick's script works... pgpYFHzjRTUoB.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Supercomputer and encryption and compression @ rate of 96%
On Thursday 14 April 2005 22:21, R. C. James Harlow wrote: You have to do that before Fredrick's script works... Damn - 'Fredrik's' - I accidentally decompressed his name. pgpbUXNRRyNvA.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Python license (2.3)
On Tuesday 12 April 2005 09:51, Antoon Pardon wrote: It seems I have to include the following in my code: Copyright (c) 2001, 2002 Python Software Foundation; All Rights Reserved Do I understand correctly? You are of course allowed to *add* your own copyright statement: Copyright (c) 2001, 2002 Python Software Foundation; All Rights Reserved Copyright (c) 2005 Antoon Pardon; All Rights Reserved pgpzG0ivpEZo9.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: database in python ?
On Monday 11 April 2005 11:01, Pierre-Frédéric Caillaud wrote: psycopg ... has a dictfetchall() method which is worth its weight in donuts ! It's very simple to write one for MySQLdb: def dictfetchall(cursor): '''Takes a MySQLdb cursor and returns the rows as dictionaries.''' col_names = [ d[0] for d in cursor.description ] return [ dict(zip(col_names, row)) for row in cur.fetchall() ] In truth, although postgres has more features, MySQL is probably better for someone who is just starting to use databases to develop for: the chances are higher that anyone using their code will have MySQL than Postgres, and they aren't going to need the features that Postgresql has that MySQL doesn't. IMO, this has changed since only a year or two ago, when MySQL didn't support foreign-key constraints. pgpIeUfcyT5Ux.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
