Re: remote multiprocessing, shared object
Thanks very much, Kushal.
But it seems to me that it doesn't quite work. After your first client
below creates l and calls append() on it, it would seem that one could
not then assign to it, e.g. do
l[1] = 8
What I'd like is to write remote multiprocessing code just like threads
code (or for that matter, just like shared-memory multiprocessing code),
i.e. reading and writing shared globals. Is this even possible?
Norm
On 2010-04-08, Kushal Kumaran kushal.kumaran+pyt...@gmail.com wrote:
On Thu, Apr 8, 2010 at 3:04 AM, Norm Matloff matl...@doe.com wrote:
Should be a simple question, but I can't seem to make it work from my
understanding of the docs.
I want to use the multiprocessing module with remote clients, accessing
shared lists. I gather one is supposed to use register(), but I don't
see exactly how. I'd like to have the clients read and write the shared
list directly, not via some kind of get() and set() functions. It's
clear how to do this in a shared-memory setting, but how can one do it
across a network, i.e. with serve_forever(), connect() etc.?
Any help, especially with a concrete example, would be much appreciated.
Thanks.
There's an example in the multiprocessing documentation.
http://docs.python.org/library/multiprocessing.html#using-a-remote-manager
It creates a shared queue, but it's easy to modify for lists.
For example, here's your shared list server:
from multiprocessing.managers import BaseManager
shared_list = []
class ListManager(BaseManager): pass
ListManager.register('get_list', callable=lambda:shared_list)
m = ListManager(address=('', 5), authkey='abracadabra')
s = m.get_server()
s.serve_forever()
A client that adds an element to your shared list:
import random
from multiprocessing.managers import BaseManager
class ListManager(BaseManager): pass
ListManager.register('get_list')
m = ListManager(address=('localhost', 5), authkey='abracadabra')
m.connect()
l = m.get_list()
l.append(random.random())
And a client that prints out the shared list:
from multiprocessing.managers import BaseManager
class ListManager(BaseManager): pass
ListManager.register('get_list')
m = ListManager(address=('localhost', 5), authkey='abracadabra')
m.connect()
l = m.get_list()
print str(l)
--
http://mail.python.org/mailman/listinfo/python-list
Re: remote multiprocessing, shared object
On Thu, Apr 8, 2010 at 11:30 AM, Norm Matloff matl...@doe.com wrote:
Thanks very much, Kushal.
But it seems to me that it doesn't quite work. After your first client
below creates l and calls append() on it, it would seem that one could
not then assign to it, e.g. do
l[1] = 8
What I'd like is to write remote multiprocessing code just like threads
code (or for that matter, just like shared-memory multiprocessing code),
i.e. reading and writing shared globals. Is this even possible?
Try this server:
from multiprocessing.managers import BaseManager, ListProxy
shared_list = []
class ListManager(BaseManager): pass
ListManager.register('get_list', callable=lambda:shared_list,
proxytype=ListProxy)
m = ListManager(address=('', 5), authkey='abracadabra')
s = m.get_server()
s.serve_forever()
Just changed the proxy type appropriately. See the managers.py file
in the multiprocessing source for details.
snipped
--
regards,
kushal
--
http://mail.python.org/mailman/listinfo/python-list
Re: Regex driving me crazy...
On Wed, 07 Apr 2010 21:57:31 -0700, Patrick Maupin wrote:
On Apr 7, 9:51 pm, Steven D'Aprano
ste...@remove.this.cybersource.com.au wrote:
BTW, I don't know how you got 'True' here.
re.split(' {2,}', s) == [x for x in s.split(' ') if x.strip()]
True
It was a copy and paste from the interactive interpreter. Here it is, in
a fresh session:
[st...@wow-wow ~]$ python
Python 2.5 (r25:51908, Nov 6 2007, 16:54:01)
[GCC 4.1.2 20070925 (Red Hat 4.1.2-27)] on linux2
Type help, copyright, credits or license for more information.
import re
s = '# 1 Short offline Completed without error 00%'
re.split(' {2,}', s) == [x for x in s.split(' ') if x.strip()]
True
Now I copy-and-paste from your latest post to do it again:
s = '# 1 Short offline Completed without error 00%'
re.split(' {2,}', s) == [x for x in s.split(' ') if x.strip()]
False
Weird, huh?
And here's the answer: somewhere along the line, something changed the
whitespace in the string into non-spaces:
s
'# 1 \xc2\xa0Short offline \xc2\xa0 \xc2\xa0 \xc2\xa0 Completed without
error \xc2\xa0 \xc2\xa0 \xc2\xa0 00%'
I blame Google. I don't know how they did it, but I'm sure it was them!
*wink*
By the way, let's not forget that the string could be fixed-width fields
padded with spaces, in which case the right solution almost certainly
will be:
s = '# 1 Short offline Completed without error 00%'
result = s[25:55].rstrip()
Even in 2010, there are plenty of programs that export data using fixed
width fields.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: Performance of list vs. set equality operations
On Wed, 07 Apr 2010 20:14:23 -0700, Raymond Hettinger wrote: [Raymond Hettinger] If the two collections have unequal sizes, then both ways immediately return unequal. [Steven D'Aprano] Perhaps I'm misinterpreting what you are saying, but I can't confirm that behaviour, at least not for subclasses of list: For doubters, see list_richcompare() in http://svn.python.org/view/python/trunk/Objects/listobject.c? revision=78522view=markup So what happens in my example with a subclass that (falsely) reports a different length even when the lists are the same? I can guess that perhaps Py_SIZE does not call the subclass __len__ method, and therefore is not fooled by it lying. Is that the case? -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple Cookie Script: Not recognising Cookie
On 8 avr, 07:03, Jimbo nill...@yahoo.com wrote:
Hi I have a simple Python program that assigns a cookie to a web user
when they open the script the 1st time(in an internet browser). If
they open the script a second time the script should display the line
You have been here 2 times. , if they open the script agai it
should show on the webpage You have been here 3 times and so on.
But for some reason, my program is not assigning or recognising an
assigned cookie outputing the line You have been here x times. I
have gone over my code for like 2 hours now I cant figure out what is
going wrong??
Can you help me figure out whats wrong? I have my own cgi server that
just runs on my machine so its not that its the code to recognise/
assign a cookie
[code]#!/usr/bin/env python
import Cookie
import cgi
import os
HTML_template =
html
head
/head
body
p %s /p
/body
/html
def main():
# Web Client is new to the site so we need to assign a cookie to
them
cookie = Cookie.SimpleCookie()
cookie['SESSIONID'] = '1'
code = No cookie exists. Welcome, this is your first visit.
if 'HTTP_COOKIE' in os.environ:
cookie = Cookie.SimpleCookie(os.environ['HTTP_COOKIE'])
# If Web client has been here before
if cookie.has_key('SESSIONID'):
cookie['SESSIONID'].value = int(cookie['SESSIONID'].value)
+1
code = You have been here %s times. %
cookie['SESSIONID'].value
else:
cookie = Cookie.SimpleCookie()
cookie['SESSIONID'] = '1'
code = I Have a cookie, but SESSIONID does not exist
print Content-Type: text/html\n
print HTML_template % code
if __name__ == __main__:
main()
[/code]
Hi,
You are confusing the cookie sent by the browser to the server - you
get it by os.environ['HTTP_COOKIE'] - and the one sent by the server
to the browser : it it sent in the response headers
You can change method main() like this :
def main():
# defaut cookie to send if web Client is new to the site
set_cookie = Cookie.SimpleCookie()
set_cookie['SESSIONID'] = 1
code = No cookie exists. Welcome, this is your first visit.
if 'HTTP_COOKIE' in os.environ:
cookie = Cookie.SimpleCookie(os.environ['HTTP_COOKIE'])
if cookie.has_key('SESSIONID'):
# web client has been here before : increment number of
visits
set_cookie['SESSIONID'] = int(cookie['SESSIONID'].value)
+1
code = You have been here %s times. %
cookie['SESSIONID'].value
else:
code = I Have a cookie, but SESSIONID does not exist
print Content-Type: text/html
print set_cookie.output() # send cookie to web client
print
print HTML_template % code
- Pierre
--
http://mail.python.org/mailman/listinfo/python-list
Re: pass object or use self.object?
Lie Ryan a écrit :
On 04/07/10 18:34, Bruno Desthuilliers wrote:
Lie Ryan a écrit :
(snip)
Since in function in python is a first-class object, you can instead do
something like:
def process(document):
# note: document should encapsulate its own logic
document.do_one_thing()
Obvious case of encapsulation abuse here. Should a file object
encapsulate all the csv parsing logic ? (and the html parsing, xml
parsing, image manipulation etc...) ? Should a model object
encapsulate the presentation logic ? I could go on for hours here...
Yes, but no; you're taking it out of context. Is {csv|html|xml|image}
parsing logic a document's logic? Is presentation a document's logic? If
they're not, then they do not belong in document.
Is len() a list logic ? If yes, it should belong to list !-)
There are two points here : the first is that we (that is, at least, you
and me) just don't know enough about the OP's project to tell whether
something should belong to the document or not. period. The second point
is that objects don't live in a splendid isolation, and it's perfectly
ok to have code outside an object's method working on the object.
wrt/ these two points, your document should encapsulate its own logic
note seems a bit dogmatic (and not necessarily right) to me - hence my
answer.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Loading an imported module (C API)
PythoidC (http://pythoidc.sourceforge.net/) provides an easy way for developing
and importing C modules into Python environment. There are some examples, may
be of some help to you.
With PythoidC, Python programmers can write, debug, commpile, C codes all in
Python IDE, and do not have to tackel the boring braces {} and line-end
semicolons ;
PythoidC automatically parses C header files, make corresponding Python
objects, thus Python programmer can essily introspect into C ... ...
CHEN Guang
- Original Message -
From: booncw chiaw...@gmail.com
To: python-list@python.org
Sent: Tuesday, April 06, 2010 9:58 PM
Subject: Loading an imported module (C API)
Hi,
I am running a simulation where the python module has already been
imported. Could you please tell me how to load it?
I've been doing this (importing everytime), but it is too slow:
pModule = PyImport_Import(pName);
Yours,
Boon
--
http://mail.python.org/mailman/listinfo/python-list
Re: Translation docstrings with gettext
Thank you for your help. Solution with decorators looks well, will try it in near future. I will report here if I solve this problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Regular Expressions
On Wed, 07 Apr 2010 18:25:36 -0700, Patrick Maupin wrote: Regular expressions != Parsers True, but lots of parsers *use* regular expressions in their tokenizers. In fact, if you have a pure Python parser, you can often get huge performance gains by rearranging your code slightly so that you can use regular expressions in your tokenizer, because that effectively gives you access to a fast, specialized C library that is built into practically every Python interpreter on the planet. Unfortunately, a typical regexp library (including Python's) doesn't allow you to match against a set of regexps, returning the index of which one matched. Which is what you really want for a tokeniser. Every time someone tries to parse nested structures using regular expressions, Jamie Zawinski kills a puppy. And yet, if you are parsing stuff in Python, and your parser doesn't use some specialized C code for tokenization (which will probably be regular expressions unless you are using mxtexttools or some other specialized C tokenizer code), your nested structure parser will be dog slow. The point is that you *cannot* match arbitrarily-nested expressions using regexps. You could, in theory, write a regexp which will match any valid syntax up to N levels of nesting, for any finite N. But in practice, the regexp is going to look horrible (and is probably going to be quite inefficient if the regexp library uses backtracking rather than a DFA). Even tokenising with Python's regexp interface is inefficient if the number of token types is large, as you have to test against each regexp sequentially. Ultimately, if you want an efficient parser, you need something with a C component, e.g. Plex. -- http://mail.python.org/mailman/listinfo/python-list
Re: Loading an imported module (C API)
On 06.04.2010 15:58, booncw wrote:
Hi,
I am running a simulation where the python module has already been
imported. Could you please tell me how to load it?
I've been doing this (importing everytime), but it is too slow:
pModule = PyImport_Import(pName);
You can cache the module object in a static variable:
static PyObject *module = NULL;
if (module == NULL (module = PyImport_ImportModuleNoBlock(module))
== NULL) {
return NULL;
}
}
Christian
--
http://mail.python.org/mailman/listinfo/python-list
Re: Performance of list vs. set equality operations
On 4/8/2010 3:07 AM, Steven D'Aprano wrote: On Wed, 07 Apr 2010 20:14:23 -0700, Raymond Hettinger wrote: [Raymond Hettinger] If the two collections have unequal sizes, then both ways immediately return unequal. [Steven D'Aprano] Perhaps I'm misinterpreting what you are saying, but I can't confirm that behaviour, at least not for subclasses of list: For doubters, see list_richcompare() in http://svn.python.org/view/python/trunk/Objects/listobject.c? revision=78522view=markup So what happens in my example with a subclass that (falsely) reports a different length even when the lists are the same? I can guess that perhaps Py_SIZE does not call the subclass __len__ method, and therefore is not fooled by it lying. Is that the case? Adding a print call within __len__ should determine that. -- http://mail.python.org/mailman/listinfo/python-list
python grep
I am in the process of reading a zipped file which is about 6gb. I would like to know if there is a command similar to grep in python because I would like to emulate, -A -B option of GNU grep. Lets say I have this, 083828.441,AA 093828.441,AA 094028.441,AA 094058.441,CC 094828.441,AA 103828.441,AA 123828.441,AA if I do grep -A2 -B2 CC I get 2 lines before and 2 lines after C Is there an easy way to do this in python? TIA -- http://mail.python.org/mailman/listinfo/python-list
Re: Translation docstrings with gettext
sapient wrote: I found several discussions where this question was asked, but was not answered. Now I am creating Python-API for my application, and want create it with translation support, including documentation strings for modules, classes, methods etc. It is simple to translate special-marked strings with gettext, but it is problem with docstrings: if I mark them for translation like _(Some documentation string) then it is not recognized as docstring. If I omit _() markup, then string is not translated. Script pygettext.py has key --docstrings that forces extraction docstrings from module, so I suppose, that it must be way to use thier translations. So, question is: How to translate docstrings in my example? You could leave the docstrings alone and monkey-patch inspect.getdoc() to do the translation when help() is invoked: #! /usr/bin/python2.6 # -*- coding: utf-8 -*- import os, gettext localedir = os.path.join( os.path.dirname(__file__), locale/ ) t = gettext.translation( 'testmodule', localedir=localedir, languages=['ru'], codeset=utf-8 ) t.install() import testmodule import inspect def getdoc(object): try: doc = object.__doc__ except AttributeError: return None if not isinstance(doc, basestring): return None return inspect.cleandoc(_(doc)) inspect.getdoc = getdoc help( testmodule ) testmodule.TestClass().testClassMethod() Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: python grep
Mag Gam, 08.04.2010 13:21: I am in the process of reading a zipped file which is about 6gb. I would like to know if there is a command similar to grep in python because I would like to emulate, -A -B option of GNU grep. Lets say I have this, 083828.441,AA 093828.441,AA 094028.441,AA 094058.441,CC 094828.441,AA 103828.441,AA 123828.441,AA if I do grep -A2 -B2 CC I get 2 lines before and 2 lines after C Is there an easy way to do this in python? Sure, just use a sliding window. However, for a 6BG file, you won't really like the performance. It's basically impossible to beat the speed of (f)grep. I'd use the subprocess module to run zfgrep over the file and parse the output in Python. Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Regular Expressions
At the moment i have less time, so its painful to read about parsing, but it is quite interessting. I have taken a look at the different Parsing Modules and i'am reading the Source Code to understand how they Work. Since Yesterday i'am writing on my own small Engine - Just for Fun and understanding how i can get what i need. It seems that this is hard to code, becouse the logic is complex and sometimes confussing. Its not easy to find a perfect solution. If someone knows good links to this thema, or can explain how parsers should/could work, please post it, or explain it. Thanks for the Informations and the Help! Kind Regards Richi -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Regular Expressions
Nobody nob...@nowhere.com wrote in message
news:pan.2010.04.08.10.12.59.594...@nowhere.com...
On Wed, 07 Apr 2010 18:25:36 -0700, Patrick Maupin wrote:
Regular expressions != Parsers
True, but lots of parsers *use* regular expressions in their
tokenizers. In fact, if you have a pure Python parser, you can often
get huge performance gains by rearranging your code slightly so that
you can use regular expressions in your tokenizer, because that
effectively gives you access to a fast, specialized C library that is
built into practically every Python interpreter on the planet.
Unfortunately, a typical regexp library (including Python's) doesn't allow
you to match against a set of regexps, returning the index of which one
matched. Which is what you really want for a tokeniser.
[snip]
Really !,
I am only a python newbie, but what about ...
import re
rr = [
( id,'([a-zA-Z][a-zA-Z0-9]*)' ),
( int, '([+-]?[0-9]+)' ),
( float, '([+-]?[0-9]+\.[0-9]*)' ),
( float, '([+-]?[0-9]+\.[0-9]*[eE][+-]?[0-9]+)' )
]
tlist = [ t[0] for t in rr ]
pat = '^ *(' + '|'.join([ t[1] for t in rr ]) + ') *$'
p = re.compile(pat)
ss = [ ' annc', '1234', 'abcd', ' 234sz ', '-1.24e3', '5.' ]
for s in ss:
m = p.match(s)
if m:
ix = [ i-2 for i in range(2,6) if m.group(i) ]
print '+s+' matches and has type, tlist[ix[0]]
else:
print '+s+' does not match
output:
' annc' matches and has type id
'1234' matches and has type int
'abcd' matches and has type id
' 234sz ' does not match
'-1.24e3' matches and has type float
'5.' matches and has type float
seems to me to match a (small) set of regular expressions and
indirectly return the index of the matched expression, without
doing a sequential loop over the regular expressions.
Of course there is a loop over the reults of the match to determine
which sub-expression matched, but a good regexp library (which
I presume Python has) should match the sub-expressions without
looping over them. The techniques to do this were well known in
the 1970's when the first versons of lex were written.
Not that I would recommend tricks like this. The regular
expression would quickly get out of hand for any non-trivial
list of regular expresssions to match.
Charles
--
http://mail.python.org/mailman/listinfo/python-list
daemon.DaemonContext
i get : IOError: [Errno 9] Bad file descriptor when i have logging and using daemon.DaemonContext() i tried passing : fh = logging.handlers.TimedRotatingFileHandler(LOG_FILENAME, 'midnight', encoding='utf-8') with : context = daemon.DaemonContext() context.files_preserve=[fh] but no good what am i doing wrong? -- http://mail.python.org/mailman/listinfo/python-list
Re: python grep
Oh, thats nice to know! But I use the CSV module with gzip module. Is it still possible to do it with the subprocess? On Thu, Apr 8, 2010 at 7:31 AM, Stefan Behnel stefan...@behnel.de wrote: Mag Gam, 08.04.2010 13:21: I am in the process of reading a zipped file which is about 6gb. I would like to know if there is a command similar to grep in python because I would like to emulate, -A -B option of GNU grep. Lets say I have this, 083828.441,AA 093828.441,AA 094028.441,AA 094058.441,CC 094828.441,AA 103828.441,AA 123828.441,AA if I do grep -A2 -B2 CC I get 2 lines before and 2 lines after C Is there an easy way to do this in python? Sure, just use a sliding window. However, for a 6BG file, you won't really like the performance. It's basically impossible to beat the speed of (f)grep. I'd use the subprocess module to run zfgrep over the file and parse the output in Python. Stefan -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
--
http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
On Apr 8, 1:28 pm, Rebelo puntabl...@gmail.com wrote:
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
Not sure, offhand.
Change to a script which just writes to the file (rather than going
via logging) - does that work? What platform are you on, what version
etc?
It's unlikely to be a logging-related problem: more likely it's to do
with file descriptors.
Regards,
Vinay Sajip
--
http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
On Apr 8, 1:28 pm, Rebelo puntabl...@gmail.com wrote:
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
My guess is - files_preserve needs to be passed a file handle and not
a logging handler.
Regards,
Vinay Sajip
--
http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
Vinay Sajip wrote:
On Apr 8, 1:28 pm, Rebelo puntabl...@gmail.com wrote:
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
My guess is - files_preserve needs to be passed a file handle and not
a logging handler.
Regards,
Vinay Sajip
thnx for help.
writing to a file works, but i need logging.
do you know where can i find good documnetation for python-daemon?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Profiling: Interpreting tottime
Gabriel Genellina gagsl-...@yahoo.com.ar writes:
En Wed, 07 Apr 2010 18:44:39 -0300, Nikolaus Rath nikol...@rath.org
escribió:
def check_s3_refcounts():
Check s3 object reference counts
global found_errors
log.info('Checking S3 object reference counts...')
for (key, refcount) in conn.query(SELECT id, refcount FROM
s3_objects):
refcount2 = conn.get_val(SELECT COUNT(inode) FROM blocks
WHERE s3key=?,
(key,))
if refcount != refcount2:
log_error(S3 object %s has invalid refcount, setting
from %d to %d,
key, refcount, refcount2)
found_errors = True
if refcount2 != 0:
conn.execute(UPDATE s3_objects SET refcount=? WHERE
id=?,
(refcount2, key))
else:
# Orphaned object will be picked up by check_keylist
conn.execute('DELETE FROM s3_objects WHERE id=?', (key,))
When I ran cProfile.Profile().runcall() on it, I got the following
result:
ncalls tottime percall cumtime percall filename:lineno(function)
1 7639.962 7639.962 7640.269 7640.269
fsck.py:270(check_s3_refcounts)
So according to the profiler, the entire 7639 seconds where spent
executing the function itself.
How is this possible? I really don't see how the above function can
consume any CPU time without spending it in one of the called
sub-functions.
Is the conn object implemented as a C extension?
No, it's pure Python.
The profiler does not
detect calls to C functions, I think.
Hmm. Isn't this a C function?
262.3170.0892.3170.089 {method 'execute' of
'apsw.Cursor' objects}
You may be interested in this package by Robert Kern:
http://pypi.python.org/pypi/line_profiler
Line-by-line profiler.
line_profiler will profile the time individual lines of code take to
execute.
That looks interesting nevertheless, thanks!
-Nikolaus
--
»Time flies like an arrow, fruit flies like a Banana.«
PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C
--
http://mail.python.org/mailman/listinfo/python-list
Re: ftp and python
You could user FTP.voidcmd()
E.G.
ftp.voidcmd('RNFT filename.txt')ftp.voidcmd('RNTO newdir/filename.txt')
From the rfc:
RENAME FROM (RNFR)
This command specifies the old pathname of the file which is
to be renamed. This command must be immediately followed by
a rename to command specifying the new file pathname.
RENAME TO (RNTO)
This command specifies the new pathname of the file
specified in the immediately preceding rename from
command. Together the two commands cause a file to be
renamed.
P.S. Sorry about emailing that direct to you John :(
On 8 April 2010 07:24, John Nagle na...@animats.com wrote:
Tim Chase wrote:
Matjaz Pfefferer wrote:
What would be the easiest way to copy files from one ftp
folder to another without downloading them to local system?
As best I can tell, this isn't well-supported by FTP[1] which doesn't seem
to have a native copy this file from server-location to server-location
bypassing the client. There's a pair of RNFR/RNTO commands that allow you
to rename (or perhaps move as well) a file which ftplib.FTP.rename()
supports but it sounds like you want too copies.
In theory, the FTP spec supports three-way transfers, where the
source, destination, and control can all be on different machines.
But no modern implementation supports that.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
get objects from image
Hallo Everybody, Maybe you can help me with this: i have a picture. The picture is black, with some white objects. Is there any way i can detect the automatically? Something like: if there white objects bigger than 3 pixels draw a box there or get their position! getting their position is more important for me. One more question: can i let the user tell the software there the white object is? like a square this moves with the mouse and the user will be able to click on the white objects. Maybe somebosy could help? with an example maybe? Thank you very much in advance Ioannis -- http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
On Apr 8, 1:58 pm, Rebelo puntabl...@gmail.com wrote:
Vinay Sajip wrote:
On Apr 8, 1:28 pm, Rebelo puntabl...@gmail.com wrote:
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
My guess is - files_preserve needs to be passed a file handle and not
alogginghandler.
Regards,
Vinay Sajip
thnx for help.
writing to a file works, but i needlogging.
do you know where can i find good documnetation for python-daemon?
No,
but see this post:
http://groups.google.com/group/comp.lang.python/msg/851ce78e53812ade
It may lead you to more information. The thread shows that Sean
DiZazzo got logging working with the package.
I think you just have to pass the file object used by the handler
(fh.stream) in the files_preserve array.
Regards,
Vinay Sajip
--
http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
i found a crude workaround: i wrote a function in which i start logging after deamon starts -- http://mail.python.org/mailman/listinfo/python-list
Re: ftp and python
Simon wrote:
You could user FTP.voidcmd()
E.G.
ftp.voidcmd('RNFT filename.txt')ftp.voidcmd('RNTO newdir/filename.txt')
From the rfc:
RENAME FROM (RNFR)
This command specifies the old pathname of the file which is
to be renamed. This command must be immediately followed by
a rename to command specifying the new file pathname.
RENAME TO (RNTO)
This command specifies the new pathname of the file
specified in the immediately preceding rename from
command. Together the two commands cause a file to be
renamed.
As mentioned in my original reply, that should be what
ftplib.FTP.rename() does under the covers[1]. However, the OP
was asking about copying a file, not renaming a file.
John mentioned the poorly-supported server-to-server copy, but
from my understanding, I think that still slurps locally and then
pushes it back up elsewhere.
-tkc
[1]
taken from ftplib.py:
def rename(self, fromname, toname):
'''Rename a file.'''
resp = self.sendcmd('RNFR ' + fromname)
if resp[0] != '3':
raise error_reply, resp
return self.voidcmd('RNTO ' + toname)
--
http://mail.python.org/mailman/listinfo/python-list
Re: daemon.DaemonContext
Vinay Sajip wrote:
On Apr 8, 1:58 pm, Rebelo puntabl...@gmail.com wrote:
Vinay Sajip wrote:
On Apr 8, 1:28 pm, Rebelo puntabl...@gmail.com wrote:
when i use this :
context = daemon.DaemonContext(stdin=sys.stdin, stdout=sys.stdout,
files_preserve=[fh], signal_map = {signal.SIGTERM:
'terminate',signal.SIGHUP: 'terminate'})
i don't get error but i still can't write to log file
what am i doing wrong?
My guess is - files_preserve needs to be passed a file handle and not
alogginghandler.
Regards,
Vinay Sajip
thnx for help.
writing to a file works, but i needlogging.
do you know where can i find good documnetation for python-daemon?
No,
but see this post:
http://groups.google.com/group/comp.lang.python/msg/851ce78e53812ade
It may lead you to more information. The thread shows that Sean
DiZazzo got logging working with the package.
I think you just have to pass the file object used by the handler
(fh.stream) in the files_preserve array.
Regards,
Vinay Sajip
thank you.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Regex driving me crazy...
On Thu, Apr 8, 2010 at 01:16, Kushal Kumaran kushal.kumaran+pyt...@gmail.com wrote: Is there any particular reason you absolutely must extract the status message? If you already have a list of possible status messages, you could just test which one of those is present in the line... Yes and no... Mostly, it's for the future. Right now, this particular test script (and I mean test script in the sense it's part of a testing framework, not in the sense that I'm being tested on it ;-) ) is fully automated. Once the self-test on the HDD is complete, the script will return either a 0 or 1 for PASS or FAIL respectively. However, in the future, it may need to be changed to or also handled manually instead of automatically. And if we end up wanting it to be automatic, then having that phrase would be important for logging or problem determination. We don't so much care about the rest of the string I want to parse as the data it gives is mostly meaningless, but having it pull things like: Completed: Electrical error or Completed: Bad Sectors Found could as useful as Completed without error or Aborted by user So that's why I was focusing on just extracting that phrase from the output. I could just pull the entire string and do a search for the phrases in question, and that's probably the simplest thing to do: re.search(Search Phrase,outputString) but I do have a tendency to overthink things some times and besides which, having just that phrase for the logs, or for use in a future change would be cool, and this way, I've already got that much of it done for later on. -- http://mail.python.org/mailman/listinfo/python-list
Re: get objects from image
On Apr 8, 9:17 am, Jannis Syntychakis ioan...@live.nl wrote: Hallo Everybody, Maybe you can help me with this: i have a picture. The picture is black, with some white objects. Is there any way i can detect the automatically? Something like: if there white objects bigger than 3 pixels draw a box there or get their position! getting their position is more important for me. One more question: can i let the user tell the software there the white object is? like a square this moves with the mouse and the user will be able to click on the white objects. Maybe somebosy could help? with an example maybe? Thank you very much in advance Ioannis Sounds like a job for an image lib, like say Camellia (http:// camellia.sourceforge.net/index.html) Their info Mentions a Ruby interface, so a python interface should be fairly easy cheers -- http://mail.python.org/mailman/listinfo/python-list
How to call application in the background with subprocess.call
Hi, I'd like to call an external application (firefox) from a python program (a PyQT GUI), but I want the external application to run in the background, I mean I do not want my python calling program to wait till the external subprocess terminates. I've tried this: call([firefox, http://www.python.org;]) but my PyQT interface freezes until I terminate Firefox. Is there any parameter I need to use with call so that the python calling program doesn't wait for the termination of the subprocess? Many thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: The Regex Story
Lie Ryan wrote: Why am I seeing a lot of this pattern lately: OP: Got problem with string +- A: Suggested a regex-based solution +- B: Quoted Some people ... regex ... two problems. or OP: Writes some regex, found problem +- A: Quoted Some people ... regex ... two problems. +- B: Supplied regex-based solution, clean one +- A: Suggested PyParsing (or similar) There's a spectrum of parsing solutions: - string.split() or string[slice] notations handle simple cases and are built-in - regexps handle more complex parsing tasks and are also built in - pyparsing handles far more complex parsing tasks (nesting, etc) but isn't built-in The above dialog tends to appear when the task isn't in the sweet-spot of regexps. Either it's sufficiently simple that simple split/slice notation will do, or (at the other end of the spectrum) the effort to get it working with a regexp is hairy and convoluted, worthy of a more readable solution implemented with pyparsing. The problem comes from people thinking that regexps are the right solution to *every* problem...often demonstrated by the OP writing how do I write a regexp to solve this non-regexp-optimal problem assuming regexps are the right tool for everything. There are some problem-classes for which regexps are the *right* solution, and I don't see as much of your example dialog in those cases. -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: How to call application in the background with subprocess.call
On Thu, Apr 8, 2010 at 7:39 PM, jorma kala jjk...@gmail.com wrote: Hi, I'd like to call an external application (firefox) from a python program (a PyQT GUI), but I want the external application to run in the background, I mean I do not want my python calling program to wait till the external subprocess terminates. I've tried this: call([firefox, http://www.python.org;]) but my PyQT interface freezes until I terminate Firefox. Is there any parameter I need to use with call so that the python calling program doesn't wait for the termination of the subprocess? Use subprocess.Popen instead of directly using subprocess.call. -- regards, kushal -- http://mail.python.org/mailman/listinfo/python-list
Re: Regex driving me crazy...
On 2010-04-08, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: Even in 2010, there are plenty of programs that export data using fixed width fields. If you want the columns to line up as the data changes, that's pretty much the only way to go. -- Grant Edwards grant.b.edwardsYow! But was he mature at enough last night at the gmail.comlesbian masquerade? -- http://mail.python.org/mailman/listinfo/python-list
Py3: Read file with Unicode characters
Attempting to read a file containing Unicode characters such as ±: UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 5007: ordinal not in range(128) I did succeed by converting all the characters to HTML entities such as #177;, but I want the characters to be the actual font in the source file. What am I doing wrong? My understanding is that ALL strings in Py3 are unicode so... confused. -- Gnarlie -- http://mail.python.org/mailman/listinfo/python-list
Re: get objects from image
lookup connected component labeling in a machine vision book. On Thu, Apr 8, 2010 at 9:57 AM, Chris Hulan chris.hu...@gmail.com wrote: On Apr 8, 9:17 am, Jannis Syntychakis ioan...@live.nl wrote: Hallo Everybody, Maybe you can help me with this: i have a picture. The picture is black, with some white objects. Is there any way i can detect the automatically? Something like: if there white objects bigger than 3 pixels draw a box there or get their position! getting their position is more important for me. One more question: can i let the user tell the software there the white object is? like a square this moves with the mouse and the user will be able to click on the white objects. Maybe somebosy could help? with an example maybe? Thank you very much in advance Ioannis Sounds like a job for an image lib, like say Camellia (http:// camellia.sourceforge.net/index.html) Their info Mentions a Ruby interface, so a python interface should be fairly easy cheers -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Py3: Read file with Unicode characters
Gnarlodious wrote: Attempting to read a file containing Unicode characters such as ±: UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 5007: ordinal not in range(128) I did succeed by converting all the characters to HTML entities such as #177;, but I want the characters to be the actual font in the source file. What am I doing wrong? My understanding is that ALL strings in Py3 are unicode so... confused. When opening the file, you need to specify the file encoding. If you don't, it defaults to ASCII (in your situation; the specific default depends on the environment). Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Performance of list vs. set equality operations
[Steven D'Aprano] So what happens in my example with a subclass that (falsely) reports a different length even when the lists are the same? I can guess that perhaps Py_SIZE does not call the subclass __len__ method, and therefore is not fooled by it lying. Is that the case? Yes. Py_SIZE() gets the actual size of the underlying list. The methods for most builtin containers typically access the underlying structure directly. That makes them fast and allows them to maintain their internal invariants. Raymond -- http://mail.python.org/mailman/listinfo/python-list
Replacing Periods with Backspaces
All,
I am trying to replace a series of periods in a sting with backspaces
that way I can easily parse information from a Windows command. the
current statement I have for this is
***Statement
capture = re.sub('\.*', '\b', capture)
===Out Put===
str: \bi\bp\bc\bo\bn\bf\bi\bg\b \b/\ba\bl\bl\b\n\b\n\bW\bi\bn\bd\bo\bw
\bs\b \bI\bP\b \bC\bo\bn\bf\bi\bg\bu\br\ba\bt\bi\bo\bn\b\n\b\n\b \b \b
\bH\bo\bs\bt\b \bN\ba\bm\be\b \b \b \b \b \b \b \b \b \b \b \b \b \b:
\b \bT\br\bi\bt\bo\bn\b\n\b \b \b \bP\br\bi\bm\ba\br\by\b \bD\bn\bs\b
\bS\bu\bf\bf\bi\bx\b \b \b \b \b \b \b \b \b \b:\b \be\bn\bg\br\bC\bo
\bl\bo\bS\bt\ba\bt\be\bE\bD\bU\b\n\b \b \b \bN\bo\bd\be\b \bT\by\bp\be
\b \b \b \b \b \b \b \b \b \b \b \b \b \b:\b \bH\by\bb\br\bi\bd\b\n\b
\b \b \bI\bP\b \bR\bo\bu\bt\bi\bn\bg\b \bE\bn\ba\bb\bl\be\bd\b \b \b
\b \b \b \b \b \b:\b \bN\bo\b\n\b \b \b \bW\bI\bN\bS\b \bP\br\bo\bx\by
\b \bE\bn\ba\bb\bl\be\bd\b \b \b \b \b \b \b \b \b:\b \bN\bo\b\n\b \b
\b \bD\bN\bS\b \bS\bu\bf\bf\bi\bx\b \bS\be\ba\br\bc\bh\b \bL\bi\bs\bt
\b \b \b \b \b \b \b:\b \be\bn\bg\br\bC\bo\bl\bo\bS\bt\ba\bt\be\bE\bD
\bU\b\n\b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b
\b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \b \bC\bo\bl\bo\bS
\bt\ba\bt\be\bE\bD\bU\b\n\b\n\bE\bt\bh\be\br\bn\be\bt\b \ba\bd\ba\bp\bt
\be\br\b \bL\bo\bc\ba\bl\b \bA\br\be\ba\b \bC\bo\bn\bn\be\bc\bt\bi\bo
\bn\b:\b\n\b\n\b \b \b \bC\bo\bn\bn\be\bc\bt\bi\bo\bn\b-\bs\bp\be\bc\bi
\bf\bi\bc\b \bD\bN\bS\b \bS\bu\bf\bf\bi\bx\b \b \b \b:\b \b\n\b \b \b
\bD\be\bs\bc\br\bi\bp\bt\bi\bo\bn\b \b \b \b \b \b \b \b \b \b \b \b
\b:\b \bR\be\ba\bl\bt\be\bk\b \bP\bC\bI\be\b \bG\bB\bE\b \bF\ba\bm\bi
\bl\by\b \bC\bo\bn\bt\br\bo\bl\bl\be\br\b\n\b \b \b \bP\bh\by\bs\bi\bc
\ba\bl\b \bA\bd\bd\br\be\bs\bs\b \b \b \b \b \b \b...
==END
which paces a bunch of '\b' strings throughout the string (to me at
random). It sort of works if I use this command but I don't want
there to be whitespace...
**Statement***
capture = re.sub('\.*', '\b', capture)
===Out Put===
str: ipconfig /all\n\nWindows IP Configuration\n\n Host
Name : Triton\n Primary Dns Suffix :
engrColoStateEDU\n Node Type : Hybrid\n IP Routing
Enabled: No\n WINS Proxy Enabled: No\n DNS Suffix
Search List : engrColoStateEDU
\n ColoStateEDU\n\nEthernet
adapter Local Area Connection:\n\n Connection-specific DNS
Suffix : \n Description: Realtek PCIe GBE Family
Controller\n Physical Address : 00-24-1D-16-FF-28\n DHCP
Enabled : No\n Autoconfiguration Enabled : Yes\n
IPv4 Address : 12982227254(Preferred) \n Subnet
Mask: 2552552480\n Default Gateway :
129822241\n DNS Servers:
1298210378\n 1298210379\n
NetBIOS over Tcpip: Enabled\n\nTunnel adapter
isatap{04FB4DF5-4B41-4058-A641-6965D13CCC06}:\n\n Media
State: Media disconnected\n Connection-specific DNS
Suffix ...
==END
If anyone can help it would be greatly appreciated.
Thanks,
Gerad Bottorff
--
http://mail.python.org/mailman/listinfo/python-list
How to open and read an unknown extension file
I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? Regards Varnika Tewari -- http://mail.python.org/mailman/listinfo/python-list
Re: python grep
Mag Gam, 08.04.2010 14:21: On Thu, Apr 8, 2010 at 7:31 AM, Stefan Behnel wrote: Mag Gam, 08.04.2010 13:21: I am in the process of reading a zipped file which is about 6gb. I would like to know if there is a command similar to grep in python because I would like to emulate, -A -B option of GNU grep. Lets say I have this, 083828.441,AA 093828.441,AA 094028.441,AA 094058.441,CC 094828.441,AA 103828.441,AA 123828.441,AA if I do grep -A2 -B2 CC I get 2 lines before and 2 lines after C Is there an easy way to do this in python? Sure, just use a sliding window. However, for a 6BG file, you won't really like the performance. It's basically impossible to beat the speed of (f)grep. I'd use the subprocess module to run zfgrep over the file and parse the output in Python. Oh, thats nice to know! But I use the CSV module with gzip module. Is it still possible to do it with the subprocess? Depends on what you do with the csv module and how it interacts with the search above. Giving more detail may allow us to answer your question and to provide better advice. Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: How to open and read an unknown extension file
On Thu, Apr 8, 2010 at 9:00 PM, varnikat t varnika...@gmail.com wrote: I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? os.path.exists does not do pattern matching like that. Take a look at the glob module. -- regards, kushal -- http://mail.python.org/mailman/listinfo/python-list
Re: Py3: Read file with Unicode characters
On Apr 8, 9:14 am, Martin v. Loewis wrote:
When opening the file, you need to specify the file encoding.
OK, I had tried this:
open(path, 'r').read().encode('utf-8')
however I get error
TypeError: Can't convert 'bytes' object to str implicitly
I had assumed a Unicode string was a Unicode string, so why is it a
bytes string?
Sorry, doing Unicode in Py3 has really been a challenge.
-- Gnarlie
--
http://mail.python.org/mailman/listinfo/python-list
Re: fcntl, serial ports and serial signals on RS232.
Max Kotasek mawr...@gmail.com writes:
Hello to all out there,
I'm trying to figure out how to parse the responses from fcntl.ioctl()
calls that modify the serial lines in a way that asserts that the line
is now changed. For example I may want to drop RTS explicitly, and
assert that the line has been dropped before returning.
Here is a brief snippet of code that I've been using to do that, but
not sure what to do with the returned response:
def set_RTS(self, state=True):
if self.fd is None:
return 0
p = struct.pack('I', termios.TIOCM_RTS)
if state:
return fcntl.ioctl(self.fd, termios.TIOCMBIS, p)
else:
return fcntl.ioctl(self.fd, termios.TIOCMBIC, p)
The problem is I get responses like '\x01\x00\x00\x00', or
'\x02\x00\x00\x00' and I'm not sure what they mean.
I'm not an expert in this by any means. However, I don't think that
fcntl call actually returns the port status after the bit setting. But
why not check it explicitly with termios.TIOCMGET? At least then I
seem to be able to toggle the RTS bit (bit 2) in the register. Here
are the trivial functions I used:
def set_rts(fd):
print Setting RTS.
p = struct.pack('I', termios.TIOCM_RTS)
fcntl.ioctl(fd, termios.TIOCMBIS, p)
def clear_rts(fd):
print Clearing RTS.
p = struct.pack('I', termios.TIOCM_RTS)
fcntl.ioctl(fd, termios.TIOCMBIC, p)
def get_status(fd):
print Querying RTS state.
stat = struct.pack('I', 0)
rc = fcntl.ioctl(fd, termios.TIOCMGET, stat)
if struct.unpack('I', rc)[0] termios.TIOCM_RTS:
print RTS bit is on.
else:
print RTS bit is off.
It seems to me also that RTS is always on after the port has been
opened. I didn't dig out my voltmeter or anything to check this,
though.
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to open and read an unknown extension file
On Thu, Apr 8, 2010 at 11:42 AM, Kushal Kumaran kushal.kumaran+pyt...@gmail.com wrote: On Thu, Apr 8, 2010 at 9:00 PM, varnikat t varnika...@gmail.com wrote: I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? os.path.exists does not do pattern matching like that. Take a look at the glob module. -- regards, kushal -- http://mail.python.org/mailman/listinfo/python-list In [4]: files = [f for f in os.listdir(os.getcwd()) if os.path.splitext(f)[-1]=='.txt'] In [5]: files Out[5]: ['pip-log.txt', 'extended_abstract.txt', 'testlog.txt', 'pymazon_error_log.txt', 'hny.txt'] -- http://mail.python.org/mailman/listinfo/python-list
catch clipboard status in gnome
Hi all,
i'ld like to create an gnome applet in python that, if left-clicked,
perform a particular operation using the text of the clipboard.
i've found this example:
import pygtk
pygtk.require('2.0')
import gtk
# get the clipboard
clipboard = gtk.clipboard_get()
# read the clipboard text data. you can also read image and
# rich text clipboard data with the
# wait_for_image and wait_for_rich_text methods.
text = clipboard.wait_for_text()
this work with cut and paste direct operation, but it doesn't catch a
selected text (that can be pasted for example in a document via the middle
clik of the mouse)
Any hints?
Nico
--
http://mail.python.org/mailman/listinfo/python-list
Re: ftp and python
John Nagle na...@animats.com writes: In theory, the FTP spec supports three-way transfers, where the source, destination, and control can all be on different machines. But no modern implementation supports that. I remember even using that way back when, Unix machines in the 1990s. But, server to server transfers are supported even today, since it's part of the RFC. RFC959 explains how it's done in chapter 5.2. Usually this is called FXP now. http://en.wikipedia.org/wiki/Comparison_of_FTP_client_software lists a bunch of clients with FXP support. I don't know about doing this with ftplib, though. -- http://mail.python.org/mailman/listinfo/python-list
Re: fcntl, serial ports and serial signals on RS232.
On 2010-04-07, Max Kotasek mawr...@gmail.com wrote: I'm trying to figure out how to parse the responses from fcntl.ioctl() calls that modify the serial lines in a way that asserts that the line is now changed. Two comments: 1) None of the Linux serial drivers I've worked on return line states except when you call TIOCMGET. 2) If the TIOCMBI[S|C] call returned a 'success' value, then the line was set to what you requested. If you want to read back the state that you just wrote, you can call TIOCMGET, but for the output pins it's always going to return the last value that was written. For example I may want to drop RTS explicitly, and assert that the line has been dropped before returning. Call TIOCMSET. If it doesn't return an error, then you're done. Here is a brief snippet of code that I've been using to do that, but not sure what to do with the returned response: What returned response? The only thing that is returned by TIOCMBIS/TIOCMBIC is a status value of 0 for success and 0 for failure. IIRC, that value is checked by Python's fcntl.ioctl wrapper and it will raise an exception on failure. Is someone familiar with manipulating serial signals like this in python? Yes. Am I even taking the right approach by using the fcntl.ioctl call? Yes. When you set/clear RTS or DTR do they not go up/down? Even if you can't use pyserial, it's a good source for example code. -- Grant Edwards grant.b.edwardsYow! TONY RANDALL! Is YOUR at life a PATIO of FUN?? gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: fcntl, serial ports and serial signals on RS232.
On 2010-04-08, Anssi Saari a...@sci.fi wrote: It seems to me also that RTS is always on after the port has been opened. I didn't dig out my voltmeter or anything to check this, though. IIRC, that's generally true: RTS and DTR are both set to on by the tty layer's open() handler _if_ the device's useage count was 0. If you open an already open port, then the RTS and DTR lines are left alone. -- Grant Edwards grant.b.edwardsYow! Someone in DAYTON, at Ohio is selling USED gmail.comCARPETS to a SERBO-CROATIAN -- http://mail.python.org/mailman/listinfo/python-list
Re: How to open and read an unknown extension file
On 04/08/2010 08:57 AM, Chris Colbert wrote: On Thu, Apr 8, 2010 at 11:42 AM, Kushal Kumaran kushal.kumaran+pyt...@gmail.com wrote: On Thu, Apr 8, 2010 at 9:00 PM, varnikat tvarnika...@gmail.com wrote: I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? os.path.exists does not do pattern matching like that. Take a look at the glob module. -- regards, kushal -- http://mail.python.org/mailman/listinfo/python-list In [4]: files = [f for f in os.listdir(os.getcwd()) if os.path.splitext(f)[-1]=='.txt'] In [5]: files Out[5]: ['pip-log.txt', 'extended_abstract.txt', 'testlog.txt', 'pymazon_error_log.txt', 'hny.txt'] seems like a lot of work from glob import glob mylist = glob( *.txt ) for item in mylist: print item -- http://mail.python.org/mailman/listinfo/python-list
Generating a rainbow?
I'm having a difficult time with this. I want to display a continuous range of hues using HTML hex representation (#RRGGBB). How would I go about scanning through the hues in order to make a rainbow? Thanks, Toby -- http://mail.python.org/mailman/listinfo/python-list
Re: Py3: Read file with Unicode characters
Gnarlodious wrote:
On Apr 8, 9:14 am, Martin v. Loewis wrote:
When opening the file, you need to specify the file encoding.
OK, I had tried this:
open(path, 'r').read().encode('utf-8')
No, when *opening* the file, you need to specify the encoding:
open(path, 'r', encoding='utf-8').read()
Sorry, doing Unicode in Py3 has really been a challenge.
That's because you need to re-learn some things.
Regards,
Martin
--
http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
On Thu, Apr 8, 2010 at 12:46 PM, Tobiah t...@rcsreg.com wrote:
I'm having a difficult time with this. I want
to display a continuous range of hues using HTML
hex representation (#RRGGBB). How would I go
about scanning through the hues in order to
make a rainbow?
Thanks,
Toby
--
http://mail.python.org/mailman/listinfo/python-list
In [43]: possible = []
In [44]: for i in range(2**8):
: h = hex(i).lstrip('0x')
: while len(h) 2:
: h = '0' + h
: possible.append(h)
:
:
In [45]: full = [r + g + b for r in possible for g in possible for b
in possible]
In [46]: len(full)
Out[46]: 16777216
In [47]: 2**24
Out[47]: 16777216
--
http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
On Apr 8, 5:46 pm, Tobiah t...@rcsreg.com wrote: I'm having a difficult time with this. I want to display a continuous range of hues using HTML hex representation (#RRGGBB). How would I go about scanning through the hues in order to make a rainbow? Thanks, Toby Look at the colorsys module. http://docs.python.org/library/colorsys.html?highlight=colorsys#module-colorsys -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
Look at the colorsys module. http://docs.python.org/library/colorsys.html?highlight=colorsys#module- colorsys That so rocks. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
How to open and read an unknown extension file
Hey, Thanks for the help.it detects now using glob.glob(*.*.txt) Can u suggest how to open and read file this way? *if glob.glob(*.*.txt): file=open(glob.glob(*.*.txt)) self.text_view.get_buffer().set_text(file.read()) else: file=open(glob.glob(*.*.html)) self.text_view.get_buffer().set_text(file.read()) * This gives error!! On Thu, Apr 8, 2010 at 9:12 PM, Kushal Kumaran kushal.kumaran+pyt...@gmail.com kushal.kumaran%2bpyt...@gmail.com wrote: On Thu, Apr 8, 2010 at 9:00 PM, varnikat t varnika...@gmail.com wrote: I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? os.path.exists does not do pattern matching like that. Take a look at the glob module. -- regards, kushal -- Varnika Tewari -- Varnika Tewari -- http://mail.python.org/mailman/listinfo/python-list
Re: How to open and read an unknown extension file
it gives me this error TypeError: coercing to Unicode: need string or buffer, list found On Thu, Apr 8, 2010 at 10:48 PM, varnikat t varnika...@gmail.com wrote: Hey, Thanks for the help.it detects now using glob.glob(*.*.txt) Can u suggest how to open and read file this way? *if glob.glob(*.*.txt): file=open(glob.glob(*.*.txt)) self.text_view.get_buffer().set_text(file.read()) else: file=open(glob.glob(*.*.html)) self.text_view.get_buffer().set_text(file.read()) * This gives error!! On Thu, Apr 8, 2010 at 9:12 PM, Kushal Kumaran kushal.kumaran+pyt...@gmail.com kushal.kumaran%2bpyt...@gmail.comwrote: On Thu, Apr 8, 2010 at 9:00 PM, varnikat t varnika...@gmail.com wrote: I am trying to do this if os.path.exists(*.*.txt): file=open(*.*.txt) self.text_view.get_buffer().set_text(file.read()) else: file=open(*.*.html) self.text_view.get_buffer().set_text(file.read()) It gives error *.*.txt not existingThere are two files in the folder testing.pnm.txt and testing.pnm.html How to make it open any name and extension file and read it? os.path.exists does not do pattern matching like that. Take a look at the glob module. -- regards, kushal -- Varnika Tewari -- Varnika Tewari -- Varnika Tewari -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
Tobiah wrote: I'm having a difficult time with this. I want to display a continuous range of hues using HTML hex representation (#RRGGBB). How would I go about scanning through the hues in order to make a rainbow? Thanks, Toby Use the hue-saturation-value color space, and call hsv_to_rgb from the standard Python library to convert to RGB. Enjoy! Gary Herron from colorsys import hsv_to_rgb for hue : rgb = hsv_to_rgb(hue, saturation, value) Let 'hue' run from 0 (red) through 2/3 (blue) Hues from 2/3 to 1 get into purples and magentas, which are not spectral (i.e., rainbow) colors. Set 'saturation' to perhaps 0.5 (for a washed out effect) through 1.0 (for pure color). Even an intensely colorful rainbow has lots of white light mixed in with it; a saturation of 0.5 is probably good. Set 'value' to something in the range of 0 to 1 to control brightness. -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
On Thu, Apr 8, 2010 at 1:14 PM, Tobiah t...@rcsreg.com wrote: Look at the colorsys module. http://docs.python.org/library/colorsys.html?highlight=colorsys#module- colorsys That so rocks. Thanks! -- http://mail.python.org/mailman/listinfo/python-list How does that answer your original question? -- http://mail.python.org/mailman/listinfo/python-list
Re: Py3: Read file with Unicode characters
On Apr 8, 11:04 am, Martin v. Loewis wrote: That's because you need to re-learn some things. Apparently so, every little item is a lesson. Thank you. -- Gnarlie -- http://mail.python.org/mailman/listinfo/python-list
Re: Replacing Periods with Backspaces
En Thu, 08 Apr 2010 12:26:56 -0300, Booter colo.av...@gmail.com escribió:
I am trying to replace a series of periods in a sting with backspaces
that way I can easily parse information from a Windows command. the
current statement I have for this is
***Statement
capture = re.sub('\.*', '\b', capture)
The * means ZERO or more occurrences - matching practically everywhere.
I think you want \.+ -- one or more occurrences of a literal period. To
actually have a \ in the string, you have to write it as \\.+ or r\.+
===Out Put===
str: \bi\bp\bc\bo\bn\bf\bi\bg\b \b/\ba\bl\bl\b\n\b\n\bW\bi\bn\bd\bo\bw
\bs\b \bI\bP\b \bC\bo\bn\bf\bi\bg\bu\br\ba\bt\bi\bo\bn\b\n\b\n\b \b \b
==END
which paces a bunch of '\b' strings throughout the string (to me at
random). It sort of works if I use this command but I don't want
there to be whitespace...
You want those \b, don't you? Just not everywhere...
===Out Put===
str: ipconfig /all\n\nWindows IP Configuration\n\n Host
Name : Triton\n Primary Dns Suffix :
engrColoStateEDU\n Node Type : Hybrid\n IP Routing
Enabled: No\n WINS Proxy Enabled: No\n DNS Suffix
Search List : engrColoStateEDU
\n ColoStateEDU\n\nEthernet
adapter Local Area Connection:\n\n Connection-specific DNS
Suffix : \n Description: Realtek PCIe GBE Family
Controller\n Physical Address : 00-24-1D-16-FF-28\n DHCP
Enabled : No\n Autoconfiguration Enabled : Yes\n
IPv4 Address : 12982227254(Preferred) \n Subnet
Mask: 2552552480\n Default Gateway :
129822241\n DNS Servers:
1298210378\n 1298210379\n
NetBIOS over Tcpip: Enabled\n\nTunnel adapter
isatap{04FB4DF5-4B41-4058-A641-6965D13CCC06}:\n\n Media
State: Media disconnected\n Connection-specific DNS
Suffix ...
==END
Except for the last '...' I don't see any '.' in that string to be
replaced...
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Why these don't work??
I'm trying the following statements that I found here and there on Google, but none of them works on my Python 2.5, are they too old? or newer? abc.reverse() import numpy -- http://mail.python.org/mailman/listinfo/python-list
Re: pass object or use self.object?
On Apr 8, 4:20 am, Bruno Desthuilliers bruno.
42.desthuilli...@websiteburo.invalid wrote:
Lie Ryan a écrit :
On 04/07/10 18:34, Bruno Desthuilliers wrote:
Lie Ryan a écrit :
(snip)
Since in function in python is a first-class object, you can instead do
something like:
def process(document):
# note: document should encapsulate its own logic
document.do_one_thing()
Obvious case of encapsulation abuse here. Should a file object
encapsulate all the csv parsing logic ? (and the html parsing, xml
parsing, image manipulation etc...) ? Should a model object
encapsulate the presentation logic ? I could go on for hours here...
Yes, but no; you're taking it out of context. Is {csv|html|xml|image}
parsing logic a document's logic? Is presentation a document's logic? If
they're not, then they do not belong in document.
Is len() a list logic ? If yes, it should belong to list !-)
There are two points here : the first is that we (that is, at least, you
and me) just don't know enough about the OP's project to tell whether
something should belong to the document or not. period. The second point
is that objects don't live in a splendid isolation, and it's perfectly
ok to have code outside an object's method working on the object.
wrt/ these two points, your document should encapsulate its own logic
note seems a bit dogmatic (and not necessarily right) to me - hence my
answer.
The 'document' in this case is an lxml Elementtree, so I think it
makes sense to have code outside the object (e.g. static methods)
working on the object.
thanks,
--Tim
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to open and read an unknown extension file
On Thu, Apr 8, 2010 at 10:39 PM, varnikat t varnika...@gmail.com wrote:
Hey,
Thanks for the help.it detects now using glob.glob(*.*.txt)
Can u suggest how to open and read file this way?
if glob.glob(*.*.txt):
file=open(glob.glob(*.*.txt))
self.text_view.get_buffer().set_text(file.read())
else:
file=open(glob.glob(*.*.html))
self.text_view.get_buffer().set_text(file.read())
This gives error!!
glob.glob returns a list of filenames. You need to loop over it and
pass individual elements to the open function.
for item in glob.glob('*.txt'):
# item is a filename. pass it to open and process however you need
I don't know how the set_text method works, but it sounds like it
might not work right if you call it repeatedly with different
filenames.
--
regards,
kushal
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
M. Hamed wrote: I'm trying the following statements that I found here and there on Google, but none of them works on my Python 2.5, are they too old? or newer? abc.reverse() import numpy reverse does not work on strings but does work on lists: x=list(abc) x.reverse() x ['c', 'b', 'a'] or maybe this: ''.join(reversed(abc)) 'cba' as far as numpy you need to install it first: http://pypi.python.org/pypi/numpy/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
On Apr 8, 7:10 pm, M. Hamed mohammed.elshou...@microchip.com wrote: I'm trying the following statements that I found here and there on Google, but none of them works on my Python 2.5, are they too old? or newer? abc.reverse() This isn't valid Python in any version that I'm aware of. Where did you see it? It wouldn't make a lot of sense anyway, since by analogy with list.reverse you'd expect it to reverse the given string in place. But that's not possible in Python, because strings are immutable. Maybe you're looking for something like: reversed(abc) reversed object at 0x100582810 which works in versions of Python = 2.4. import numpy For this to work, you need to have numpy installed. numpy is a third- party package that isn't part of the standard Python distribution; for more information, see: http://numpy.scipy.org/ The best method for installing numpy would depend on your system, and on where you got Python from. On OS X, the system Python comes with numpy as standard, for example. On Linux, there's probably a python26- numpy package (or something with a similar name) that you can install. On Windows: no idea. :) Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
How does that answer your original question? I was able to do this: import colorsys sat = 1 value = 1 length = 1000 for x in range(0, length + 1): hue = x / float(length) color = list(colorsys.hsv_to_rgb(hue, sat, value)) for x in range(3): color[x] = int(color[x] * 255) hexval = (#%02x%02x%02x % tuple(color)).upper() print div style='height: 1; width: 500; background-color: %s' % hexval http://tobiah.org/rainbow.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
M. Hamed wrote: I'm trying the following statements that I found here and there on Google, but none of them works on my Python 2.5, are they too old? or newer? abc.reverse() Lists have a .reverse() method which reverses the list elements in-place, but strings don't because they're immutable. There's a built-in function reversed() which returns an iterator over an iterable object, eg a string: print reversed(abc) for c in reversed(abc): print c It's all in the documentation. import numpy numpy isn't part of the standard library; you'd need to download and install it. -- http://mail.python.org/mailman/listinfo/python-list
Re: ftp and python
Anssi Saari wrote: John Nagle na...@animats.com writes: In theory, the FTP spec supports three-way transfers, where the source, destination, and control can all be on different machines. But no modern implementation supports that. I remember even using that way back when, Unix machines in the 1990s. But, server to server transfers are supported even today, since it's part of the RFC. RFC959 explains how it's done in chapter 5.2. Usually this is called FXP now. http://en.wikipedia.org/wiki/Comparison_of_FTP_client_software lists a bunch of clients with FXP support. I don't know about doing this with ftplib, though. Although the protocol allows setting up a 3-way transfer, many FTP servers disallow data connections to an IP address different from the control address. It's a security risk. It's useful when you want to move data between machines with high bandwidth connections, as within a server farm, and the control machine has less bandwidth. But there are more modern approaches for that. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
regex help: splitting string gets weird groups
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried:
re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$',
'555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
--
http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
gry wrote:
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried:
re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$', '555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
If the regex was illegal then it would raise an exception. It's doing
exactly what you're asking it to do!
First of all, there are 4 groups, with group 1 containing groups 2..4 as
alternatives, so group 1 will match whatever groups 2..4 match:
Group 1: (([A-Za-z]+)|([0-9]+)|([-.#=]))
Group 2: ([A-Za-z]+)
Group 3: ([0-9]+)
Group 4: ([-.#=])
It matches like this:
Group 1 and group 3 match '555'.
Group 1 and group 2 match 'tHe'.
Group 1 and group 4 match '-'.
Group 1 and group 2 match 'rain'.
Group 1 and group 4 match '.'.
Group 1 and group 2 match 'in'.
Group 1 and group 4 match '#'.
Group 1 and group 4 match '='.
Group 1 and group 3 match '1234'.
If a group matches then any earlier match of that group is discarded,
so:
Group 1 finishes with '1234'.
Group 2 finishes with 'in'.
Group 3 finishes with '1234'.
Group 4 finishes with '='.
A solution is:
re.findall('[A-Za-z]+|[0-9]+|[-.#=]', '555tHe-rain.in#=1234')
['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234']
Note: re.findall() returns a list of matches, so if the regex doesn't
contain any groups then it returns the matched substrings. Compare:
re.findall(a(.), ax ay)
['x', 'y']
re.findall(a., ax ay)
['ax', 'ay']
--
http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
On 8 Apr, 19:49, gry georgeryo...@gmail.com wrote:
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried: re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$',
'555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
I would avoid .match and use .findall
(if you walk through them both together, it'll make sense what's
happening
with your match string).
s = 555tHe-rain.in#=1234
re.findall('[A-Za-z]+|[0-9]+|[-.#=]', s)
['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234']
hth,
Jon.
--
http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
On Apr 8, 1:49 pm, gry georgeryo...@gmail.com wrote:
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried: re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$',
'555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
IMO, for most purposes, for people who don't want to become re
experts, the easiest, fastest, best, most predictable way to use re is
re.split. You can either call re.split directly, or, if you are going
to be splitting on the same pattern over and over, compile the pattern
and grab its split method. Use a *single* capture group in the
pattern, that covers the *whole* pattern. In the case of your example
data:
import re
splitter=re.compile('([A-Za-z]+|[0-9]+|[-.#=])').split
s='555tHe-rain.in#=1234'
[x for x in splitter(s) if x]
['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234']
The reason for the list comprehension is that re.split will always
return a non-matching string between matches. Sometimes this is
useful even when it is a null string (see recent discussion in the
group about splitting digits out of a string), but if you don't care
to see null (empty) strings, this comprehension will remove them.
The reason for a single capture group that covers the whole pattern is
that it is much easier to reason about the output. The split will
give you all your data, in order, e.g.
''.join(splitter(s)) == s
True
HTH,
Pat
--
http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
gry wrote:
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried:
re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$', '555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
well, I'm not sure what it thinks its finding but nested capture-groups
always produce somewhat weird results for me (I suspect that's what's
triggering the duplication). Additionally, you're only searching for
one match (.match() returns a single match-object or None; not all
possible matches within the repeated super-group).
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
Tweaking your original, I used
s='555tHe-rain.in#=1234'
import re
r=re.compile(r'([a-zA-Z]+|\d+|.)')
r.findall(s)
['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234']
The only difference between my results and your results is that the 555
and 1234 come back as strings, not ints.
-tkc
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
Thanks All. That clears alot of confusion. It seems I assumed that everything that works for lists works for strings (the immutable vs mutable hasn't sunken in yet). On the other hand (other than installing NumPy) is there a built-in way to do an array full of zeros or one just like the numpy.zeros()? I know I can do it with list comprehension (like [0 for i in range(0,20)] but these are too many keystrokes for python :) I was wondering if there is a simpler way. I had another question about arrays but I should probably start another thread. Regards, On Apr 8, 11:43 am, MRAB pyt...@mrabarnett.plus.com wrote: M. Hamed wrote: I'm trying the following statements that I found here and there on Google, but none of them works on my Python 2.5, are they too old? or newer? abc.reverse() Lists have a .reverse() method which reverses the list elements in-place, but strings don't because they're immutable. There's a built-in function reversed() which returns an iterator over an iterable object, eg a string: print reversed(abc) for c in reversed(abc): print c It's all in the documentation. import numpy numpy isn't part of the standard library; you'd need to download and install it. -- http://mail.python.org/mailman/listinfo/python-list
Dynamically growing an array to implement a stack
I have trouble with some Python concept. The fact that you can not assign to a non-existent index in an array. For example: a = [0,1] a[2] = Generates an error I can use a.append(2) but that always appends to the end. Sometimes I want to use this array as a stack and hence my indexing logic would be something like: If you are already at the end (based on your stack pointer): use append() then index (and inc your pointer) if not: index directly (and inc your stack pointer) If feel that doing this everytime I want to add an element that I have to check whether it exists or not is too much. Is there any simpler way to do this? I know I can do something like this: a = numpy.zeros(MAX_STACK_SIZE) but I don't want to predetermine the stack size. Any help? Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
On 4/8/2010 1:08 PM M. Hamed said... On the other hand (other than installing NumPy) is there a built-in way to do an array full of zeros or one just like the numpy.zeros()? I know I can do it with list comprehension (like [0 for i in range(0,20)] but these are too many keystrokes for python :) I was wondering if there is a simpler way. map(lambda _:0, range(20)) Emile -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamically growing an array to implement a stack
On Apr 8, 3:21 pm, M. Hamed mhels...@hotmail.com wrote: I have trouble with some Python concept. The fact that you can not assign to a non-existent index in an array. For example: a = [0,1] a[2] = Generates an error I can use a.append(2) but that always appends to the end. Sometimes I want to use this array as a stack and hence my indexing logic would be something like: If you are already at the end (based on your stack pointer): use append() then index (and inc your pointer) if not: index directly (and inc your stack pointer) ??? The stack pointer is *always* at the end, except don't actually keep a real stack pointer, let list do it for you. Call append to push a value onto the end, and pop to pull it off. Or if you are really stuck on push/pop commands for a stack, do this: class stack(list): ... push = list.append ... ss = stack() ss.push(x) ss.push(Y) ss ['x', 'Y'] ss.pop() 'Y' ss.pop() 'x' ss.pop() Traceback (most recent call last): File stdin, line 1, in module IndexError: pop from empty list -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamically growing an array to implement a stack
On Apr 8, 3:21 pm, M. Hamed mhels...@hotmail.com wrote: I have trouble with some Python concept. The fact that you can not assign to a non-existent index in an array. For example: a = [0,1] a[2] = Generates an error I can use a.append(2) but that always appends to the end. Sometimes I want to use this array as a stack and hence my indexing logic would be something like: If you are already at the end (based on your stack pointer): use append() then index (and inc your pointer) if not: index directly (and inc your stack pointer) If feel that doing this everytime I want to add an element that I have to check whether it exists or not is too much. Is there any simpler way to do this? I know I can do something like this: a = numpy.zeros(MAX_STACK_SIZE) but I don't want to predetermine the stack size. Any help? Thanks Well, if you never want to add intermediate data between your new element and the stack, you can just do: stack[index:index + 1] = [newelement] Regards, Pat -- http://mail.python.org/mailman/listinfo/python-list
Re: Recommend Commercial graphing library
Grant Edwards inva...@invalid.invalid writes: If it's 2D data, you don't need to use a 3D graph. if it's tabular data, you don't need an uber-histogram -- giampippetto, coso, come si chiama? ah si` MMAX ha scritto: Tra il trascendente e l'interpretazione prevalente del dato come assioma ne passa... -- http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
On 2010-04-08 15:08 PM, M. Hamed wrote: On the other hand (other than installing NumPy) is there a built-in way to do an array full of zeros or one just like the numpy.zeros()? I know I can do it with list comprehension (like [0 for i in range(0,20)] but these are too many keystrokes for python :) I was wondering if there is a simpler way. [0] * n Of course, you should keep in mind that you shouldn't always be looking for concise built-in expressions to do things. Or rather, you shouldn't be disappointed if you don't find them. Almost always, the best solution is to wrap up the ugly code into a function that you can then call everywhere. So even if you were stuck with the list comprehension, you should have just defined your own zeros() function that did the job and use it everywhere. -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
On Apr 8, 3:40 pm, MRAB pyt...@mrabarnett.plus.com wrote: ... Group 1 and group 4 match '='. Group 1 and group 3 match '1234'. If a group matches then any earlier match of that group is discarded, Wow, that makes this much clearer! I wonder if this behaviour shouldn't be mentioned in some form in the python docs? Thanks much! so: Group 1 finishes with '1234'. Group 2 finishes with 'in'. Group 3 finishes with '1234'. -- http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
On 8 Apr, 19:49, gry georgeryo...@gmail.com wrote:
[ python3.1.1, re.__version__='2.2.1' ]
I'm trying to use re to split a string into (any number of) pieces of
these kinds:
1) contiguous runs of letters
2) contiguous runs of digits
3) single other characters
e.g. 555tHe-rain.in#=1234 should give: [555, 'tHe', '-', 'rain',
'.', 'in', '#', '=', 1234]
I tried: re.match('^(([A-Za-z]+)|([0-9]+)|([-.#=]))+$',
'555tHe-rain.in#=1234').groups()
('1234', 'in', '1234', '=')
Why is 1234 repeated in two groups? and why doesn't tHe appear as a
group? Is my regexp illegal somehow and confusing the engine?
I *would* like to understand what's wrong with this regex, though if
someone has a neat other way to do the above task, I'm also interested
in suggestions.
Avoiding re's (for a bit of fun):
(no good for unicode obviously)
import string
from itertools import groupby, chain, repeat, count, izip
s = 555tHe-rain.in#=1234
unique_group = count()
lookup = dict(
chain(
izip(string.ascii_letters, repeat('L')),
izip(string.digits, repeat('D')),
izip(string.punctuation, unique_group)
)
)
parse = dict(D=int, L=str.capitalize)
print [ parse.get(key, lambda L: L)(''.join(items)) for key, items in
groupby(s, lambda L: lookup[L]) ]
[555, 'The', '-', 'Rain', '.', 'In', '#', '=', 1234]
Jon.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
On Apr 8, 10:08 pm, M. Hamed mohammed.elshou...@microchip.com
wrote:
Thanks All. That clears alot of confusion. It seems I assumed that
everything that works for lists works for strings (the immutable vs
mutable hasn't sunken in yet).
On the other hand (other than installing NumPy) is there a built-in
way to do an array full of zeros or one just like the numpy.zeros()? I
know I can do it with list comprehension (like [0 for i in
range(0,20)] but these are too many keystrokes for python :) I was
wondering if there is a simpler way.
I had another question about arrays but I should probably start
another thread.
Regards,
On Apr 8, 11:43 am, MRAB pyt...@mrabarnett.plus.com wrote:
M. Hamed wrote:
I'm trying the following statements that I found here and there on
Google, but none of them works on my Python 2.5, are they too old? or
newer?
abc.reverse()
Lists have a .reverse() method which reverses the list elements
in-place, but strings don't because they're immutable.
There's a built-in function reversed() which returns an iterator over an
iterable object, eg a string:
print reversed(abc)
for c in reversed(abc):
print c
It's all in the documentation.
import numpy
numpy isn't part of the standard library; you'd need to download and
install it.
if you want an array you can get it from module array
import array
array.array('i', [0]*100)
array('i', [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
if you want simply a list:
[0] * 100
yields a list of hundred zeros
cheers
joaquin
--
http://mail.python.org/mailman/listinfo/python-list
Re: python as pen and paper substitute
Manuel Graune manuel.gra...@koeln.de writes: Hello everyone, I am looking for ways to use a python file as a substitute for simple pen and paper calculations. search(embedded calc mode) if manuel in emacs_fellows_set or sys.exit(1) -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
Tobiah wrote: How does that answer your original question? I was able to do this: import colorsys sat = 1 value = 1 length = 1000 for x in range(0, length + 1): hue = x / float(length) color = list(colorsys.hsv_to_rgb(hue, sat, value)) for x in range(3): color[x] = int(color[x] * 255) hexval = (#%02x%02x%02x % tuple(color)).upper() print div style='height: 1; width: 500; background-color: %s' % hexval http://tobiah.org/rainbow.html Roy G. Biv would like you to order the colors according to their wavelength. He would also like to see Orange and Yellow appear in your rainbow. -- http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
s='555tHe-rain.in#=1234' import re r=re.compile(r'([a-zA-Z]+|\d+|.)') r.findall(s) ['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234'] This is nice and simple and has the invertible property that Patrick mentioned above. Thanks much! -- http://mail.python.org/mailman/listinfo/python-list
Re: python as pen and paper substitute
Giacomo Boffi giacomo.bo...@polimi.it writes: Manuel Graune manuel.gra...@koeln.de writes: Hello everyone, I am looking for ways to use a python file as a substitute for simple pen and paper calculations. search(embedded calc mode) if manuel in emacs_fellows_set or sys.exit(1) Well, the subject does say python and not elisp, but I'm a vim-user anyways. *duckandrun* -- A hundred men did the rational thing. The sum of those rational choices was called panic. Neal Stephenson -- System of the world http://www.graune.org/GnuPG_pubkey.asc Key fingerprint = 1E44 9CBD DEE4 9E07 5E0A 5828 5476 7E92 2DB4 3C99 -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamically growing an array to implement a stack
Thanks Patrick, that is what I was exactly looking for. Paul, thanks for your example. wasn't familiar with the stack class. I feel Patrick's method is a lot simpler for my purpose. Regards. On Apr 8, 1:29 pm, Patrick Maupin pmau...@gmail.com wrote: On Apr 8, 3:21 pm, M. Hamed mhels...@hotmail.com wrote: I have trouble with some Python concept. The fact that you can not assign to a non-existent index in an array. For example: a = [0,1] a[2] = Generates an error I can use a.append(2) but that always appends to the end. Sometimes I want to use this array as a stack and hence my indexing logic would be something like: If you are already at the end (based on your stack pointer): use append() then index (and inc your pointer) if not: index directly (and inc your stack pointer) If feel that doing this everytime I want to add an element that I have to check whether it exists or not is too much. Is there any simpler way to do this? I know I can do something like this: a = numpy.zeros(MAX_STACK_SIZE) but I don't want to predetermine the stack size. Any help? Thanks Well, if you never want to add intermediate data between your new element and the stack, you can just do: stack[index:index + 1] = [newelement] Regards, Pat -- http://mail.python.org/mailman/listinfo/python-list
Re: Why these don't work??
OMG! That's beautiful! I loved the [0]*n how simple and how it never
occurred to me!
Robert I agree with your comment. I feel though that since I'm not
very experienced yet with Python, it's useful to learn about all those
simple yet powerful methods so I can use them when I really need them.
Plus it gives me more justification for the time I invested learning a
new language (and glad I did), and more reasons to dump Perl forever!
Thanks for all the suggestions.
On Apr 8, 1:37 pm, Joaquin Abian gatoyga...@gmail.com wrote:
On Apr 8, 10:08 pm, M. Hamed mohammed.elshou...@microchip.com
wrote:
Thanks All. That clears alot of confusion. It seems I assumed that
everything that works for lists works for strings (the immutable vs
mutable hasn't sunken in yet).
On the other hand (other than installing NumPy) is there a built-in
way to do an array full of zeros or one just like the numpy.zeros()? I
know I can do it with list comprehension (like [0 for i in
range(0,20)] but these are too many keystrokes for python :) I was
wondering if there is a simpler way.
I had another question about arrays but I should probably start
another thread.
Regards,
On Apr 8, 11:43 am, MRAB pyt...@mrabarnett.plus.com wrote:
M. Hamed wrote:
I'm trying the following statements that I found here and there on
Google, but none of them works on my Python 2.5, are they too old? or
newer?
abc.reverse()
Lists have a .reverse() method which reverses the list elements
in-place, but strings don't because they're immutable.
There's a built-in function reversed() which returns an iterator over an
iterable object, eg a string:
print reversed(abc)
for c in reversed(abc):
print c
It's all in the documentation.
import numpy
numpy isn't part of the standard library; you'd need to download and
install it.
if you want an array you can get it from module array
import array
array.array('i', [0]*100)
array('i', [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
if you want simply a list: [0] * 100
yields a list of hundred zeros
cheers
joaquin
--
http://mail.python.org/mailman/listinfo/python-list
Re: regex help: splitting string gets weird groups
On Apr 8, 3:40 pm, gry georgeryo...@gmail.com wrote: s='555tHe-rain.in#=1234' import re r=re.compile(r'([a-zA-Z]+|\d+|.)') r.findall(s) ['555', 'tHe', '-', 'rain', '.', 'in', '#', '=', '1234'] This is nice and simple and has the invertible property that Patrick mentioned above. Thanks much! Yes, like using split(), this is invertible. But you will see a difference (and for a given task, you might prefer one way or the other) if, for example, you put a few consecutive spaces in the middle of your string, where this pattern and findall() will return each space individually, and split() will return them all together. You *can* fix up the pattern for findall() where it will have the same properties as the split(), but it will almost always be a more complicated pattern than for the equivalent split(). Another thing you can do with split(): if you *think* you have a pattern that fully covers every string you expect to throw at it, but would like to verify this, you can make use of the fact that split() returns a string between each match (and before the first match and after the last match). So if you expect that every character in your entire string should be a part of a match, you can do something like: strings = splitter(s) tokens = strings[1::2] assert not ''.join(strings[::2]) Regards, Pat -- http://mail.python.org/mailman/listinfo/python-list
Re: The Regex Story
On 4/9/10, Tim Chase python.l...@tim.thechases.com wrote: Lie Ryan wrote: Why am I seeing a lot of this pattern lately: OP: Got problem with string +- A: Suggested a regex-based solution +- B: Quoted Some people ... regex ... two problems. or OP: Writes some regex, found problem +- A: Quoted Some people ... regex ... two problems. +- B: Supplied regex-based solution, clean one +- A: Suggested PyParsing (or similar) There's a spectrum of parsing solutions: snip The above dialog tends to appear when the task isn't in the sweet-spot of regexps. Either it's sufficiently simple that simple split/slice notation will do, or (at the other end of the spectrum) the effort to get it working with a regexp is hairy and convoluted, worthy of a more readable solution implemented with pyparsing. The problem comes from people thinking that regexps are the right solution to *every* problem...often demonstrated by the OP writing how do I write a regexp to solve this non-regexp-optimal problem assuming regexps are the right tool for everything. There are some problem-classes for which regexps are the *right* solution, and I don't see as much of your example dialog in those cases. I would have agreed with you if someone were to make the statement until a few weeks ago; somehow in the last week or so, the mood about regex seems to has shifted to regex is not suitable for anything type of mood. As soon as someone (OP or not) proposed a regex solution, someone else would retort with don't use regex use string-builtins or pyparsing. It appears that the group has developed some sense of regexphobia; some people pushes using string builtins for moderately complex requirement and suggested pyparsing for not-so complex need and that keeps shrinking regex sweet spot. But that's just my inherently subjective observation. -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
Tobiah: for x in range(0, length + 1): ... for x in range(3): You should use different variables for the two loops. Neil -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
Me: You should use different variables for the two loops. Actually it is closing the divs that makes it work in FireFox: import colorsys sat = 1 value = 1 length = 1000 for h in range(0, length + 1): hue = h / float(length) color = list(colorsys.hsv_to_rgb(hue, sat, value)) for x in range(3): color[x] = int(color[x] * 255) hexval = (#%02x%02x%02x % tuple(color)).upper() print( div style='height: 1; width: 500; background-color: %s' /div % hexval) -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a rainbow?
On Thu, Apr 8, 2010 at 2:34 PM, Tobiah t...@rcsreg.com wrote: How does that answer your original question? I was able to do this: import colorsys sat = 1 value = 1 length = 1000 for x in range(0, length + 1): hue = x / float(length) color = list(colorsys.hsv_to_rgb(hue, sat, value)) for x in range(3): color[x] = int(color[x] * 255) hexval = (#%02x%02x%02x % tuple(color)).upper() print div style='height: 1; width: 500; background-color: %s' % hexval http://tobiah.org/rainbow.html -- http://mail.python.org/mailman/listinfo/python-list I see. It appears I misunderstood the question. The link doesn't work in Chrome btw. -- http://mail.python.org/mailman/listinfo/python-list
Pythonic list reordering
I have a list... ['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat', 'dir_330_error.dat'] I want to sort it based upon the numerical value only. Does someone have an elegant solution to this? Thanks, Ben R. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonic list reordering
On Thu, Apr 8, 2010 at 3:52 PM, Ben Racine i3enha...@gmail.com wrote:
I have a list...
['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat',
'dir_330_error.dat']
I want to sort it based upon the numerical value only.
a = ['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat',
'dir_330_error.dat']
def key(item):
return int(item.split('_')[1])
a.sort(key=key)
Cheers,
Chris
--
http://blog.rebertia.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Pythonic list reordering
Ben Racine wrote:
I have a list...
['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat',
'dir_330_error.dat']
I want to sort it based upon the numerical value only.
Does someone have an elegant solution to this?
Thanks,
Ben R.
How about a one liner?
L.sort(key=lambda s: int(s.split('_')[1]))
(Which is not necessarily elegant, but it is short.)
Gary Herron
--
http://mail.python.org/mailman/listinfo/python-list
Re: Pythonic list reordering
On Apr 9, 12:52 am, Ben Racine i3enha...@gmail.com wrote:
I have a list...
['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat',
'dir_330_error.dat']
I want to sort it based upon the numerical value only.
Does someone have an elegant solution to this?
Thanks,
Ben R.
not sure about elegance, but my two cents:
mylist = ['dir_0_error.dat', 'dir_120_error.dat', 'dir_30_error.dat',
'dir_330_error.dat']
mylist = [(int(item.split('_')[1]), item) for item in mylist]
mylist.sort()
mylist = [item for idx, item in mylist]
mylist
['dir_0_error.dat', 'dir_30_error.dat', 'dir_120_error.dat',
'dir_330_error.dat']
joaquin
--
http://mail.python.org/mailman/listinfo/python-list
