[ANN] RedNotebook 0.9.1
Version 0.9.1 of RedNotebook has just been released. You can get it at http://rednotebook.sourceforge.net What is RedNotebook? RedNotebook is a graphical diary and journal helping you keep track of notes and thoughts. It includes a calendar navigation, customizable templates, export functionality and word clouds. You can also format, tag and search your entries. Packages are available for common Linux distributions and Windows. What's new? --- * Markup highlighting is now much faster * Webkit can now be used for previews (in the config file, set useWebkit to 1). * Make welcome text translatable * Add comments for translators * Make help available online Cheers, Jendrik -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
cx_Freeze 4.1.2
What is cx_Freeze? cx_Freeze is a set of scripts and modules for freezing Python scripts into executables in much the same way that py2exe and py2app do. It requires Python 2.3 or higher since it makes use of the zip import facility which was introduced in that version. Where do I get it? http://cx-freeze.sourceforge.net What's new? Changes from 4.1.1 to 4.1.2 1) Fix bug that caused the util extension to be named improperly. 2) Fix bug that prevented freezing from taking place if a packaged submodule was missing. 3) Fix bug that prevented freezing from taking place in Python 3.x if the encoding of the source file wasn't compatible with the encoding of the terminal performing the freeze. 4) Fix bug that caused the base modules to be included in the library.zip as well as the base executables. -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
Galway Python Meetup - Wed, Feb 3rd, 2010 - 19:00
Hi All, When - Wed Feb 3rd 2010, 19:00 Where - Westwood Bar, Westwood House Hotel, Dangan, Newcastle, Galway Contact - Michael Kerrin Details up at http://www.python.ie/meetup/2010/galway_python_meetup_-_feb_2010/ Thanks again to Michael for arranging this event. Here's hoping for more Python meetups outside of Dublin. ;) Cheers, /// Vicky ~~ ~~ http://irishbornchinese.com ~~ ~~ http://www.python.ie ~~ ~~ -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
Re: Object Relational Mappers are evil (a meditation)
J Kenneth King wrote: In many contexts I'm sure there is reason to use Perl instead of Python just as there are situations where C is more appropriate than either. However, the mark of a poor programmer in my line of reasoning is one who cannot recognize such distinctions. One must be aware of the benefits and short-comings of their tools. If your tools influence the way you think then you are being ignorant of this principle. And I would suggest that makes you a poor programmer. Perhaps influence the way you think is not the right way to phrase it... how about be the tool ;) We have all seen the struggles that newcomers to a language go through as they try (or don't try) to adjust their thinking to the tool at hand -- programming Java, BASIC, FORTRAN, or xyz in Python. Even now Phlip is raging against exceptions and the very Zen of Python. Converting FoxPro to Python is an interesting excercise for me -- version 6 at least doesn't have many of the cool things that Python does, and consequently thinking in Python while writing FoxPro (when I have to) is extremely frustrating; going the other way is a bit of a challenge also, although much more rewarding. For a more concrete example, take sail-boats and speed-boats: you get used to the speed boat, it's quick handling and sharp turns... then you take a sail boat out for a cruise -- if you don't adjust your thinking from speed to sail, you could very well end up in the rocks. To sum up: I agree with your poor programmer line of reasoning in the second paragraph above, but not with the tools influencing the way we think line of reasoning -- while I am cognizant of Python's shortcomings, I am very much enjoying the changes in my thinking the more I use it. ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list
RE: lxml 2.2.4 on python3.1, Windows XP gives importerror
Posting again as I did not get any response: Dear All I have Python 3.1 installed on Windows XP and Works nice. I downloaded lxml 2.2.4 (lxml-2.2.4.win32-py3.1.exe) from pypi. When I try: from lxml import etree I get: ImportError: DLL load failed: This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem. For information: 'import lxml' works fine. After reinstalling python3.1 also the error message is the same. Any help is appreciated! Regards, Ashish Vyas -- http://mail.python.org/mailman/listinfo/python-list
Re: unittest inconsistent
André wrote: On Jan 5, 8:14 pm, Matt Haggard haggar...@gmail.com wrote: Can anyone tell me why this test fails? http://pastebin.com/f20039b17 This is a minimal example of a much more complex thing I'm trying to do. I'm trying to hijack a function and inspect the args passed to it by another function. The reason the 'Tester' object has no attribute 'arg1' is because self still refers to the object made for testA. Quick answer: change faketest.py as follows: #-- # faketest.py #-- #from importme import render import importme def run(somearg): return importme.render(somearg) = A long answer, with explanation, will cost you twice as much ;-) (but will have to wait) André Or you figure it out yourself staring at import os from os import rename os.rename = 42 rename built-in function rename os.rename 42 from module import name binds the object referred to by module.name to the name variable in the current module. You can think of it as a shortcut for import module name = module.name del module When you later rebind import module module.name = something_else the reference in the current module isn't magically updated to point to something_else. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
r0g aioe@technicalbloke.com writes: NO! It's a rude way to start a sentence don't you think? Shouting is usually rude, yes. Just because you're correcting someone doesn't mean you have to be combative and try and make them feel small. Again, you're reading something that isn't there. I utterly deny the motives you're imputing. I can't imagine why I expect good manners on usenet though, AFAICT it's never been like that (well not since I got on it anyway). I'll reiterate that you can address this by paying more attention to what is actually written, and endeavouring to avoid finding emotions or motives that are likely not in the message. -- \“The greatest tragedy in mankind's entire history may be the | `\ hijacking of morality by religion.” —Arthur C. Clarke, 1991 | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: chown'ing by script
On Wed, Jan 6, 2010 at 2:12 AM, alex23 wuwe...@gmail.com wrote: Carsten Haese carsten.ha...@gmail.com wrote: What is the underlying problem you're trying to solve with this approach? To be paid for developing a web site shopping cart without actually having to learn Python. LOL! I've written about 12,000 lines of code in this, BTW. Crawl back into your cave :) beno -- http://mail.python.org/mailman/listinfo/python-list
Need help to pass self.count to other classes.
After a year with Python 2.5 on my Windows box, I still have trouble understanding classes. Below, see the batch file and the configuration script for my Python interactive prompt. The widths of the secondary prompts increase when the self.count of SysPrompt1 exceeds 99. I am using a global variable zxc to share self.count, which is not Pythonic. How can I pass in self.count without a global? I did RTFM, aka Google, but to no avail. echo py.bat set PYTHONSTARTUP=c:\scripts\startup.py python ^Z # startup.py # inspired by: # http://www.doughellmann.com/PyMOTW/sys/interpreter.html import sys class SysPrompt1(object): def __init__(self): self.count = 0 def __str__(self): self.count += 1 global zxc zxc = self.count return '[%2d] ' % self.count class SysPrompt2(object): def __str__(self): global zxc if zxc 99: return '.. ' else: return '. ' class DisplayHook(object): def __call__(self, value): if value is None: return global zxc if zxc 99: print '[ out]', value, '\n' else: print '[out]', value, '\n' class ExceptHook(object): def __call__(self, type, value, trace): global zxc if zxc 99: print '[ err]', value, '\n' else: print '[err]', value, '\n' sys.ps1 = SysPrompt1() sys.ps2 = SysPrompt2() sys.displayhook = DisplayHook() sys.excepthook = ExceptHook() -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to pass self.count to other classes.
On 6 Gen, 11:11, Bill bsag...@gmail.com wrote: After a year with Python 2.5 on my Windows box, I still have trouble understanding classes. Below, see the batch file and the configuration script for my Python interactive prompt. The widths of the secondary prompts increase when the self.count of SysPrompt1 exceeds 99. I am using a global variable zxc to share self.count, which is not Pythonic. How can I pass in self.count without a global? I did RTFM, aka Google, but to no avail. echo py.bat set PYTHONSTARTUP=c:\scripts\startup.py python ^Z # startup.py # inspired by: #http://www.doughellmann.com/PyMOTW/sys/interpreter.html import sys class SysPrompt1(object): def __init__(self): self.count = 0 def __str__(self): self.count += 1 global zxc zxc = self.count return '[%2d] ' % self.count class SysPrompt2(object): def __str__(self): global zxc if zxc 99: return '.. ' else: return '. ' class DisplayHook(object): def __call__(self, value): if value is None: return global zxc if zxc 99: print '[ out]', value, '\n' else: print '[out]', value, '\n' class ExceptHook(object): def __call__(self, type, value, trace): global zxc if zxc 99: print '[ err]', value, '\n' else: print '[err]', value, '\n' sys.ps1 = SysPrompt1() sys.ps2 = SysPrompt2() sys.displayhook = DisplayHook() sys.excepthook = ExceptHook() First of all, you shouldn't do OOP if you don't feel it. Python, unlike Java and like C++, supports also procedural programming, so you can write your scripts without writing classes (but still using objects, since all in python is an object). If you have classes with no data and a single __call_ method, then they are no classes, they are functions (or methods) in disguise. So, one solution could be to use plain functions and use global as you already do. 'global' is pythonic if you are not doing OOP, although I don't like it. If you want to stick to OOP, then I suggest to have a make display_hook and except_hook methods of your class SysPrompt1; This way all your code can access to self.count without needing globals. As for your class SysPrompt2, I don't understand enough your code to know what you are trying to do. maybe make it a sunclass of SysPrompt1 ? HTH Ciao FB -- http://mail.python.org/mailman/listinfo/python-list
Convert month name to month number faster
I'm optimizing the inner most loop of my script. I need to convert month
name to month number. I'm using python 2.6 on linux x64.
month_dict = {Jan:1,Feb:2,Mar:3,Apr:4, May:5, Jun:6,
Jul:7,Aug:8,Sep:9,Oct:10,Nov:11,Dec:12}
def to_dict(name):
return month_dict[name]
def to_if(name):
if name == Jan: return 1
elif name == Feb: return 2
elif name == Mar: return 3
elif name == Apr: return 4
elif name == May: return 5
elif name == Jun: return 6
elif name == Jul: return 7
elif name == Aug: return 8
elif name == Sep: return 9
elif name == Oct: return 10
elif name == Nov: return 11
elif name == Dec: return 12
else: raise ValueError
import random
l = [random.choice(month_dict.keys()) for _ in range(100)]
from time import time
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 1.0
is there a faster solution? Maybe something with str.translate?
The problem is a little different because I don't read random data, but
sorted data. For example:
l = [x for x in
(Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec)
for _ in range(1000)] # [Jan,Jan, ..., Feb, Feb, ...]
so maybe the to_if approach will be faster if I write the case in the best
order. Look:
l = [Jan] * 100 # to_if is in the best order for Jan
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 0.5
--
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RE: Convert month name to month number faster
How about using list.index() and storing month names in a list? You may
want to measure performance your self and conclude.
Regards,
Ashish Vyas
-Original Message-
From: python-list-bounces+ntb837=motorola@python.org
[mailto:python-list-bounces+ntb837=motorola@python.org] On Behalf Of
wiso
Sent: Wednesday, January 06, 2010 4:34 PM
To: python-list@python.org
Subject: Convert month name to month number faster
I'm optimizing the inner most loop of my script. I need to convert month
name to month number. I'm using python 2.6 on linux x64.
month_dict = {Jan:1,Feb:2,Mar:3,Apr:4, May:5, Jun:6,
Jul:7,Aug:8,Sep:9,Oct:10,Nov:11,Dec:12}
def to_dict(name):
return month_dict[name]
def to_if(name):
if name == Jan: return 1
elif name == Feb: return 2
elif name == Mar: return 3
elif name == Apr: return 4
elif name == May: return 5
elif name == Jun: return 6
elif name == Jul: return 7
elif name == Aug: return 8
elif name == Sep: return 9
elif name == Oct: return 10
elif name == Nov: return 11
elif name == Dec: return 12
else: raise ValueError
import random
l = [random.choice(month_dict.keys()) for _ in range(100)]
from time import time
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 1.0
is there a faster solution? Maybe something with str.translate?
The problem is a little different because I don't read random data, but
sorted data. For example:
l = [x for x in
(Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec
)
for _ in range(1000)] # [Jan,Jan, ..., Feb, Feb, ...]
so maybe the to_if approach will be faster if I write the case in the
best
order. Look:
l = [Jan] * 100 # to_if is in the best order for Jan
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 0.5
--
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--
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Re: Convert month name to month number faster
Le Wed, 06 Jan 2010 12:03:36 +0100, wiso a écrit : from time import time t = time(); xxx=map(to_dict,l); print time() - t # 0.5 t = time(); xxx=map(to_if,l); print time() - t # 1.0 Don't define your own function just for attribute access. Instead just write: xxx = map(month_dict.__getitem__, l) -- http://mail.python.org/mailman/listinfo/python-list
[no subject]
Hi,
Well, it seems that one of your files is a different architecture than
the others. Based on the location, I'd say it's i386 while the rest of
it would be PowerPC. You can cross-compile but you can't link an i386
library to a PowerPC library.
Thank you for the hint. I have checked with file command the format of the
libraries on mac and got following result:
one of my application's libraries:
libkkbase.dylib: Mach-O dynamically linked shared library i386
my python module that has been built using standard python distutils:
j3k.so: Mach-O bundle i386
I am not actually sure what's the difference between bundle and dynamically
linked shared library on mac and if they can be linked together? Perhaps I
should configure distutils on mac somehow specially to make the module ready
for embedding?
Thanks,
KK
On Tue, Jan 5, 2010 at 7:33 AM, Krzysztof Kobus kk720...@yahoo.com wrote:
Hi,
I have a problem with linking python module with my application on mac
in order to make the module available in embedded python.
My python module is contained in j3kmodule.cxx file and module
initialization function is exported in j3kmodule.h
j3kmodule.h:
PyMODINIT_FUNC PyInit_j3k(void);
j3kmodule.cxx:
--
PyMODINIT_FUNC
PyInit_j3k(void)
{
PyObject *m = NULL;
if ((m = PyModule_Create(j3k_module)) == NULL)
return NULL;
return m;
}
Then in my application in KkPython.cxx file I have:
KkPython.cxx:
-
#include j3kmodule.h
/* Add a builtin module, before Py_Initialize */
PyImport_AppendInittab(j3k, PyInit_j3k);
I link my application with the module and get following linking error
on mac although on open suse linux exactly the same procedure works
fine:
g++ -headerpad_max_install_names -o
../../bin/render.app/Contents/MacOS/render main.o KkPython.o -lkkbase
-L/Users/kk/dev/J3K/trunk/j3ksrc/examples/render/../../lib/
-lQtSolutions_PropertyBrowser-2.5 -lpython3.1
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so
-framework OpenGL -framework AGL
ld: warning in
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so,
file is not of required architecture
Undefined symbols:
_PyInit_j3k, referenced from:
_PyInit_j3k$non_lazy_ptr in KkPython.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [../../bin/render.app/Contents/MacOS/render] Error 1
I appreciate any hints,
best greetings,
Krzysztof Kobus
--
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how to change when the logging module creates the log file?
I have an application the writes to a log file when specific exceptions are
handled. However, if no exceptions are encountered, I don't want to create a
log at all.
The problem I am running into is that the stdlib logging module creates the
log file immediately upon logger instantiation.
Thus:
logger = logging.basicConifg('testlog.txt')
already creates the file 'testlog.txt'.
So, at program close, I am reading the size of the log file, and if it is
empty I remove it with os.remove(). This works fine on Linux, but throws a
permission denied exception on Windows.
There has to be a better way to do this than using a hack like that. Is
there a way to make the logging module hold-off on file creation until the
first log is generated? I could do it by wrapping logger in a class, but
that would remove the beauty of having any module import logging from the
stdlib and being able to write to the log.
Thanks for any pointers!
Chris
--
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Re: embedded python on mac - linking problem
Hi,
Well, it seems that one of your files is a different architecture than
the others. Based on the location, I'd say it's i386 while the rest of
it would be PowerPC. You can cross-compile but you can't link an i386
library to a PowerPC library.
Thank you for the hint. I have checked with file command the format of the
libraries on mac and got following result:
one of my application's libraries:
libkkbase.dylib: Mach-O dynamically linked shared library i386
my python module that has been built using standard python distutils:
j3k.so: Mach-O bundle i386
I am not actually sure what's the difference between bundle and dynamically
linked shared library on mac and if they can be linked together? Perhaps I
should configure distutils on mac somehow specially to make the module ready
for
embedding?
Thanks,
KK
On Tue, Jan 5, 2010 at 7:33 AM, Krzysztof Kobus wrote:
Hi,
I have a problem with linking python module with my application on mac
in order to make the module available in embedded python.
My python module is contained in j3kmodule.cxx file and module
initialization
function is exported in j3kmodule.h
j3kmodule.h:
PyMODINIT_FUNC PyInit_j3k(void);
j3kmodule.cxx:
--
PyMODINIT_FUNC
PyInit_j3k(void)
{
PyObject *m = NULL;
if ((m = PyModule_Create(j3k_module)) == NULL)
return NULL;
return m;
}
Then in my application in KkPython.cxx file I have:
KkPython.cxx:
-
#include j3kmodule.h
/* Add a builtin module, before Py_Initialize */
PyImport_AppendInittab(j3k, PyInit_j3k);
I link my application with the module and get following linking error
on mac although on open suse linux exactly the same procedure works
fine:
g++ -headerpad_max_install_names -o
../../bin/render.app/Contents/MacOS/render main.o KkPython.o -lkkbase
-L/Users/kk/dev/J3K/trunk/j3ksrc/examples/render/../../lib/
-lQtSolutions_PropertyBrowser-2.5 -lpython3.1
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so
-framework OpenGL -framework AGL
ld: warning in
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so,
file is not of required architecture
Undefined symbols:
_PyInit_j3k, referenced from:
_PyInit_j3k$non_lazy_ptr in KkPython.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [../../bin/render.app/Contents/MacOS/render] Error 1
I appreciate any hints,
best greetings,
Krzysztof Kobus
--
http://mail.python.org/mailman/listinfo/python-list
Re: Convert month name to month number faster
On Jan 6, 9:03 pm, wiso gtu2...@alice.it wrote:
I'm optimizing the inner most loop of my script. I need to convert month
name to month number. I'm using python 2.6 on linux x64.
month_dict = {Jan:1,Feb:2,Mar:3,Apr:4, May:5, Jun:6,
Jul:7,Aug:8,Sep:9,Oct:10,Nov:11,Dec:12}
def to_dict(name):
return month_dict[name]
Try replacing the to_dict function with:
to_dict = month_dict.get
That removes one extra function call per lookup. On my computer, this
reduces the time for your test from 0.26 to 0.09.
--
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Re: Convert month name to month number faster
Antoine Pitrou wrote: Le Wed, 06 Jan 2010 12:03:36 +0100, wiso a écrit : from time import time t = time(); xxx=map(to_dict,l); print time() - t # 0.5 t = time(); xxx=map(to_if,l); print time() - t # 1.0 Don't define your own function just for attribute access. Instead just write: xxx = map(month_dict.__getitem__, l) t = time(); xxx=map(month_dict.__getitem__,l); print time() - t # 0.2 month_list = (,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec) t = time(); xxx=map(month_list.index,l); time() - t # 0.6 -- http://mail.python.org/mailman/listinfo/python-list
creating tar file and streaming it over HTTP?
I would like to bundle up a number of files in a tar file and send it over a HTTP connection, but I would like to do this without creating the tar file on disk first. I know I can get tarfile to output to a stream by doing something like tar_pipe = tarfile.open(mode=w|, fileobj=my_file_obj) However, I can't figure out which file object to use to send this over a HTTP connection. I tried conn = httplib.HTTPConnection(hostname, port) conn.putrequest(PUT, /client/files) conn.endheaders() tar_pipe = tarfile.open(mode=w|, fileobj=conn.sock.makefile()) for filename in filenames: tar_pipe.add(filename) tar_pipe.close() conn.getresponse() but that does not send any data... -- http://mail.python.org/mailman/listinfo/python-list
Re: Convert month name to month number faster
On Wed, 06 Jan 2010 12:03:36 +0100, wiso wrote:
I'm optimizing the inner most loop of my script. I need to convert month
name to month number. I'm using python 2.6 on linux x64.
According to your own figures below, it takes less than a nanosecond per
lookup, at worst, even using a remarkably inefficient technique. Are you
trying to tell us that this is the bottleneck in your script? I'm sorry,
I find that implausible. I think you're wasting your time trying to
optimise something that doesn't need optimizing.
Even if you halve the time, and deal with a million data points each time
you run your script, you will only save half a second per run. I can see
from the times you posted that you've spent at least an hour trying to
optimise this. To make up for that one hour, you will need to run your
script 7200 times, before you see *any* time savings at all.
month_dict = {Jan:1,Feb:2,Mar:3,Apr:4, May:5, Jun:6,
Jul:7,Aug:8,Sep:9,Oct:10,Nov:11,Dec:12}
def to_dict(name):
return month_dict[name]
This leads to a pointless function call. Just call month_dict[name]
instead of calling a function that calls it.
def to_if(name):
if name == Jan: return 1
elif name == Feb: return 2
elif name == Mar: return 3
elif name == Apr: return 4
elif name == May: return 5
elif name == Jun: return 6
elif name == Jul: return 7
elif name == Aug: return 8
elif name == Sep: return 9
elif name == Oct: return 10
elif name == Nov: return 11
elif name == Dec: return 12
else: raise ValueError
That is remarkably awful.
import random
l = [random.choice(month_dict.keys()) for _ in range(100)]
from time import time
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 1.0
This is not a reliable way to do timings. You should use the timeit
module.
is there a faster solution? Maybe something with str.translate?
What makes you think str.translate is even remotely useful for this?
--
Steven
--
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Re: fsync() doesn't work as advertised?
On Jan 5, 1:08 pm, Nobody nob...@nowhere.com wrote: On Mon, 04 Jan 2010 08:09:56 -0800, Brian D wrote: If I'm running a process in a loop that runs for a long time, I occasionally would like to look at a log to see how it's going. I know about the logging module, and may yet decide to use that. Still, I'm troubled by howfsync() doesn't seem to work as advertised: http://docs.python.org/library/os.html If you’re starting with a Python file object f, first do f.flush(), and then do os.fsync(f.fileno()) The .flush() method (and the C fflush() function) causes the contents of application buffers to be sent to the OS, which basically copies the data into the OS-level buffers. fsync() causes the OS-level buffers to be written to the physical drive. File operations normally use the OS-level buffers; e.g. if one process write()s to a file and another process read()s it, the latter will see what the former has written regardless of whether the data has been written to the drive. The main reason for usingfsync() is to prevent important data from being lost in the event of an unexpected reboot or power-cycle (an expected reboot via the shutdown or halt commands will flush all OS-level buffers to the drive first). Other than that,fsync() is almost invisible (I say almost, as there are mechanisms to bypass the OS-level buffers, e.g. the O_DIRECT open() flag). An excellent explanation of the process. I've seen this in other programming environments, so I could visualize something to that effect, but couldn't have verbalized it. I certainly have a better idea what's happening. Thanks for the contribution. -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to pass self.count to other classes.
Bill a écrit : After a year with Python 2.5 on my Windows box, I still have trouble understanding classes. Below, see the batch file and the configuration script for my Python interactive prompt. The widths of the secondary prompts increase when the self.count of SysPrompt1 exceeds 99. I am using a global variable zxc to share self.count, which is not Pythonic. It's not unpythonic - but it's not good OO style neither !-) How can I pass in self.count without a global? (snip) sys.ps1 = SysPrompt1() sys.ps2 = SysPrompt2() sys.displayhook = DisplayHook() sys.excepthook = ExceptHook() hint #1: a bound method is also a callable. hint #2: an object can be an attribute of another object. Possible OO solution: class Counter(object): def __init__(self): self._count = 0 def inc(self): self._count += 1 value = property(fget=lambda s: s._count) class Prompt1(object): def __init__(self, counter): self._counter = counter def _str_(self): self._counter.inc() return '[%2d] ' % self._counter.value class Prompt2(object): def __init__(self, counter): self._counter = counter def _str_(self): if self._counter.value 99: # XXX magic number return '.. ' else: return '. ' class MySysHookHandler(object): def __init__(self): self._counter = Counter() self.ps1 = Prompt1(self._counter) self.ps2 = Prompt2(self._counter) def displayhook(self, value): if value is None: return if self._counter.value 99: # XXX magic number print '[ out]', value, '\n' else: print '[out]', value, '\n' def excepthook(self, type, value, trace): if self._counter.value 99: # XXX magic number print '[ err]', value, '\n' else: print '[err]', value, '\n' handler = MySysHook() sys.ps1 = handler.ps1 sys.ps2 = handler.ps2 sys.displayhook = handler.displayhook sys.excepthook = handler.excepthook HTH -- http://mail.python.org/mailman/listinfo/python-list
Re: Do I have to use threads?
On Jan 6, 2010, at 12:45 AM, Brian J Mingus wrote: On Tue, Jan 5, 2010 at 9:36 PM, Philip Semanchuk phi...@semanchuk.comwrote: On Jan 5, 2010, at 11:26 PM, aditya shukla wrote: Hello people, I have 5 directories corresponding 5 different urls .I want to download images from those urls and place them in the respective directories.I have to extract the contents and download them simultaneously.I can extract the contents and do then one by one. My questions is for doing it simultaneously do I have to use threads? No. You could spawn 5 copies of wget (or curl or a Python program that you've written). Whether or not that will perform better or be easier to code, debug and maintain depends on the other aspects of your program(s). bye Philip Obviously, spawning 5 copies of wget is equivalent to starting 5 threads. The answer is 'yes'. ??? Process != thread -- http://mail.python.org/mailman/listinfo/python-list
Re: creating tar file and streaming it over HTTP?
pbienst wrote: I would like to bundle up a number of files in a tar file and send it over a HTTP connection, but I would like to do this without creating the tar file on disk first. I know I can get tarfile to output to a stream by doing something like tar_pipe = tarfile.open(mode=w|, fileobj=my_file_obj) However, I can't figure out which file object to use to send this over a HTTP connection. I tried conn = httplib.HTTPConnection(hostname, port) conn.putrequest(PUT, /client/files) conn.endheaders() tar_pipe = tarfile.open(mode=w|, fileobj=conn.sock.makefile()) for filename in filenames: tar_pipe.add(filename) tar_pipe.close() conn.getresponse() but that does not send any data... I haven't used socket.makefile() in a blue age so this is untested, but I'm guessing you need a *write* file (remember, sockets have two directions). So try fileobj=conn.sock.makefile(w)... and let me know if that helps. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Do I have to use threads?
On Wed, Jan 6, 2010 at 6:24 AM, Philip Semanchuk phi...@semanchuk.comwrote: On Jan 6, 2010, at 12:45 AM, Brian J Mingus wrote: On Tue, Jan 5, 2010 at 9:36 PM, Philip Semanchuk phi...@semanchuk.com wrote: On Jan 5, 2010, at 11:26 PM, aditya shukla wrote: Hello people, I have 5 directories corresponding 5 different urls .I want to download images from those urls and place them in the respective directories.I have to extract the contents and download them simultaneously.I can extract the contents and do then one by one. My questions is for doing it simultaneously do I have to use threads? No. You could spawn 5 copies of wget (or curl or a Python program that you've written). Whether or not that will perform better or be easier to code, debug and maintain depends on the other aspects of your program(s). bye Philip Obviously, spawning 5 copies of wget is equivalent to starting 5 threads. The answer is 'yes'. ??? Process != thread Just like the other nitpicker it is up to you to explain why the differences, and not he similarities, are relevant to this problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to pass self.count to other classes.
Bill wrote: After a year with Python 2.5 on my Windows box, I still have trouble understanding classes. Below, see the batch file and the configuration script for my Python interactive prompt. The widths of the secondary prompts increase when the self.count of SysPrompt1 exceeds 99. I am using a global variable zxc to share self.count, which is not Pythonic. How can I pass in self.count without a global? I did RTFM, aka Google, but to no avail. echo py.bat set PYTHONSTARTUP=c:\scripts\startup.py python ^Z # startup.py # inspired by: # http://www.doughellmann.com/PyMOTW/sys/interpreter.html import sys class SysPrompt1(object): def __init__(self): self.count = 0 def __str__(self): self.count += 1 global zxc zxc = self.count return '[%2d] ' % self.count class SysPrompt2(object): def __str__(self): global zxc if zxc 99: return '.. ' else: return '. ' class DisplayHook(object): def __call__(self, value): if value is None: return global zxc if zxc 99: print '[ out]', value, '\n' else: print '[out]', value, '\n' class ExceptHook(object): def __call__(self, type, value, trace): global zxc if zxc 99: print '[ err]', value, '\n' else: print '[err]', value, '\n' sys.ps1 = SysPrompt1() sys.ps2 = SysPrompt2() sys.displayhook = DisplayHook() sys.excepthook = ExceptHook() As Francesco points out, OO programming isn't *mandatory* in Python. However, if you used a single class instead of multiples then you could use an instance variable for zxc, and have each of the functions be bound methods (i.e. methods of the instance, not the class). This is untested code (some days I don't seem to write any other kind ...) but it should give you the flavor: class kbInterface(object): def __init__(self): self.zxc = 0 def prompt1(self): self.count += 1 return [%d] def prompt2(self): l = len(str(self.count))+1 return %s % .*l def dhook(self, value): print [%d out] % self.count def ehook(self, type, value, trace): print [%d err]\n % value kbi = kbInterface() sys.ps1 = kbi.prompt1 sys.ps2 = kbi.prompt2 sys.displayhook = kbi.dhook sys.excepthook = kbi.ehook Do you get the idea? Now the count is shared between all the methods, and it's available in the instance's namespace. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: chown'ing by script
Victor Subervi wrote: On Wed, Jan 6, 2010 at 2:12 AM, alex23 wuwe...@gmail.com mailto:wuwe...@gmail.com wrote: Carsten Haese carsten.ha...@gmail.com mailto:carsten.ha...@gmail.com wrote: What is the underlying problem you're trying to solve with this approach? To be paid for developing a web site shopping cart without actually having to learn Python. LOL! I've written about 12,000 lines of code in this, BTW. Crawl back into your cave :) beno Which, I don't doubt, could have been 2,000 lines had you bothered to take the excellent advice you've been offered on learning Python. Still, the better the advice the worse it's wasted ... regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python] Re: Printing plain text with exact positioning on Windows
KvS wrote: Ok, actually I quite like being able to print straightforward through your code, i.e. without any extra modules installed. I understand that sending text to the printer is in principle as simple as dc.TextOut(scale_factor * 72, -1 * scale_factor * 72, Testing...) I didn't see you do anything with adjusting margins in the code. Does that mean that if I would e.g. do dc.TextOut(0, 0, Testing...) the printout would appear in the upper left corner of the paper, as close to the edges as the printer is capable of? (Sorry, but I only have Ubuntu available at the moment, no Windows). Actually, as I understand it (and I'll admit my understanding is a bit flawed in some areas), when you tell MSWinPrint.py to print at (0, 0), you are telling it to print at the actual paper edge; if that's outside the printable area (and it probably is for most printers), your printing will be cut off. Best thing to do is to try it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Do I have to use threads?
On 04:26 am, adityashukla1...@gmail.com wrote: Hello people, I have 5 directories corresponding 5 different urls .I want to download images from those urls and place them in the respective directories.I have to extract the contents and download them simultaneously.I can extract the contents and do then one by one. My questions is for doing it simultaneously do I have to use threads? Please point me in the right direction. See Twisted, http://twistedmatrix.com/ in particular, Twisted Web's asynchronous HTTP client, http://twistedmatrix.com/documents/current/web/howto/client.html http://twistedmatrix.com/documents/current/api/twisted.web.client.html Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamic text color
On 2010-01-05, John Posner jjpos...@optimum.net wrote: 2. It's probably not the best idea to use a single variable (you use file) to do double-duty: to hold the name of a file, and to hold the open-file object returned by the open() function. It's perfectly legal, but it hides information that might be useful when you're debugging a program. This is better: fname = 'red.txt' inpf = open(fname, r) Alternatively: infile = open(red.txt, r) infile.name 'red.txt' -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
Re: embedded python on mac - linking problem
Krzysztof Kobus schrieb:
Hi,
I have a problem with linking python module with my application on mac in order to make
the module available in embedded python.
My python module is contained in j3kmodule.cxx file and module initialization
function is exported in j3kmodule.h
j3kmodule.h:
PyMODINIT_FUNC PyInit_j3k(void);
j3kmodule.cxx:
--
PyMODINIT_FUNC
PyInit_j3k(void)
{
PyObject *m = NULL;
if ((m = PyModule_Create(j3k_module)) == NULL)
return NULL;
return m;
}
Then in my application in KkPython.cxx file I have:
KkPython.cxx:
-
#include j3kmodule.h
/* Add a builtin module, before Py_Initialize */
PyImport_AppendInittab(j3k, PyInit_j3k);
I link my application with the module and get following linking error on mac
although on open suse linux exactly the same procedure works fine:
g++ -headerpad_max_install_names -o ../../bin/render.app/Contents/MacOS/render
main.o KkPython.o -lkkbase
-L/Users/kk/dev/J3K/trunk/j3ksrc/examples/render/../../lib/
-lQtSolutions_PropertyBrowser-2.5 -lpython3.1
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so
-framework OpenGL -framework AGL
ld: warning in
/Users/kk/dev/J3K/trunk/j3ksrc/python/modules/build/lib.macosx-10.3-i386-3.1/j3k.so,
file is not of required architecture
Undefined symbols:
_PyInit_j3k, referenced from:
_PyInit_j3k$non_lazy_ptr in KkPython.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [../../bin/render.app/Contents/MacOS/render] Error 1
I appreciate any hints,
The missing symbol looks like a C++-symbol - but Python is C. Do you
maybe miss the
extern C
declaration.
Diez
--
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Python books, literature etc
Greetings list I can code in Python (strong beginner), and would like to read more books and/or online resources. Could someone please point out any good books, websites, tutorials etc to help me get to the next level. Your help insight highly appreciated :) Stuart -- http://mail.python.org/mailman/listinfo/python-list
Re: Printing plain text with exact positioning on Windows
On Jan 5, 7:16 pm, Nobody nob...@nowhere.com wrote: On Tue, 05 Jan 2010 04:40:14 -0800, KvS wrote: Did you mean borderless printing? Every printer needs his margins, some more some less. Some printers have the ability to do borderless printing but usualy they can do it only on special or photo paper. So you can adjust the pdf as you wish, even with no margins, and then try to find under printer options borderless printing. That is why I didn't understand :-)) it is a printer thing not pdf! As much as possible borderless, yes. Of course the printer will still apply some small margin, but that's ok. A margin of say 0.5 cm. is fine. So it's not a printer thing, I accept the (physical) limitations of the printer, but I want to avoid any extra margins due to software settings. Hardcopy document formats such as PostScript and PDF use positions relative to the edges of the page, not the margins. Right. Still, Acrobat Reader by default scales the contents to fit on a page and creates some margins by doing so, no? So if my text is close to the left and right edges, as I want, it will get scaled and extra margins will occur. Avoiding this still requires me to be able to turn off this scaling in the printing preferences somehow programmatically, so it doesn't seem to make the problem easier? -- http://mail.python.org/mailman/listinfo/python-list
Re: Printing plain text with exact positioning on Windows
On Jan 5, 11:40 am, KvS keesvansch...@gmail.com wrote: On Jan 5, 7:16 pm, Nobody nob...@nowhere.com wrote: On Tue, 05 Jan 2010 04:40:14 -0800, KvS wrote: Did you mean borderless printing? Every printer needs his margins, some more some less. Some printers have the ability to do borderless printing but usualy they can do it only on special or photo paper. So you can adjust the pdf as you wish, even with no margins, and then try to find under printer options borderless printing. That is why I didn't understand :-)) it is a printer thing not pdf! As much as possible borderless, yes. Of course the printer will still apply some small margin, but that's ok. A margin of say 0.5 cm. is fine. So it's not a printer thing, I accept the (physical) limitations of the printer, but I want to avoid any extra margins due to software settings. Hardcopy document formats such as PostScript and PDF use positions relative to the edges of the page, not the margins. Right. Still, Acrobat Reader by default scales the contents to fit on a page and creates some margins by doing so, no? So if my text is close to the left and right edges, as I want, it will get scaled and extra margins will occur. Avoiding this still requires me to be able to turn off this scaling in the printing preferences somehow programmatically, so it doesn't seem to make the problem easier? Maybe you could have the user print your data on a larger sheet of paper;one that is sure to include all of the data, and include crop marks on the printout. The user then cuts along the crop marks to leave a perfectly sized, marginless page. This is how printers do bleeds. -- http://mail.python.org/mailman/listinfo/python-list
Online math-coding contest
Hi , we gladly invite you to take part in Athena - the Online Math Coding Contest of Kurukshetra 2010 , the International Techo-Management Fest organised by College Of Engineering Guindy , India under the patronage of UNESCO . Here's your chance to lock horns against the best minds across the globe and showcase your algorithmic prowess and mathematical acumen !! Participants from 20+ countries already registered!! catch the action at www.athena.kurukshetra.org.in Exciting prizes to be won !! For queries please contact ath...@kurukshetra.org.in Dates : Practice contest : 6th January 5.00 P.M Indian Standard Time Main contest : 8th January - 15th January awaiting your presence , Team Athena -- http://mail.python.org/mailman/listinfo/python-list
unittest inconsistent
Can anyone tell me why this test fails? http://pastebin.com/f20039b17 This is a minimal example of a much more complex thing I'm trying to do. I'm trying to hijack a function and inspect the args passed to it by another function. The reason the 'Tester' object has no attribute 'arg1' is because self still refers to the object made for testA. -- http://mail.python.org/mailman/listinfo/python-list
Re: Printing plain text with exact positioning on Windows
If this is, by any chance, an HP printer, the printer may support PCL 5 (or a similar language). I've written PCL scripts (in Pascal, so a while ago) to precisely print points at the printer resolution (i.e., I picked which six-hundredth of an inch in height and width dimensions to print a dot. PCL 5 absolutely would let you put text anywhere you wanted, including the absolute limits on margins that the hardware supports. (PCL is printer control language). Gerry -- http://mail.python.org/mailman/listinfo/python-list
Re: Python books, literature etc
Search Google. You'll find it all. Search this list's archives. This kind of thing has been discussed a thousand times. It also wouldn't hurt to brush up on this: http://catb.org/~esr/faqs/smart-questions.html -- http://mail.python.org/mailman/listinfo/python-list
Re: chown'ing by script
On Wed, 06 Jan 2010 08:58:13 -0500 Steve Holden st...@holdenweb.com wrote: Victor Subervi wrote: [Usual nonsense removed] Which, I don't doubt, could have been 2,000 lines had you bothered to Steve - any chance that you could stop replying to this idiot or at least do it privately. There's not much point to kill-filing someone if someone else is just going to repeat his posts. -- D'Arcy J.M. Cain da...@druid.net | Democracy is three wolves http://www.druid.net/darcy/| and a sheep voting on +1 416 425 1212 (DoD#0082)(eNTP) | what's for dinner. -- http://mail.python.org/mailman/listinfo/python-list
RE: Convert month name to month number faster
VYAS ASHISH M-NTB837 wrote:
How about using list.index() and storing month names in a list? You may
want to measure performance your self and conclude.
Regards,
Ashish Vyas
-Original Message-
From: python-list-bounces+ntb837=motorola@python.org
[mailto:python-list-bounces+ntb837=motorola@python.org] On Behalf Of
wiso
Sent: Wednesday, January 06, 2010 4:34 PM
To: python-list@python.org
Subject: Convert month name to month number faster
I'm optimizing the inner most loop of my script. I need to convert month
name to month number. I'm using python 2.6 on linux x64.
month_dict = {Jan:1,Feb:2,Mar:3,Apr:4, May:5, Jun:6,
Jul:7,Aug:8,Sep:9,Oct:10,Nov:11,Dec:12}
def to_dict(name):
return month_dict[name]
def to_if(name):
if name == Jan: return 1
elif name == Feb: return 2
elif name == Mar: return 3
elif name == Apr: return 4
elif name == May: return 5
elif name == Jun: return 6
elif name == Jul: return 7
elif name == Aug: return 8
elif name == Sep: return 9
elif name == Oct: return 10
elif name == Nov: return 11
elif name == Dec: return 12
else: raise ValueError
import random
l = [random.choice(month_dict.keys()) for _ in range(100)]
from time import time
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 1.0
is there a faster solution? Maybe something with str.translate?
The problem is a little different because I don't read random data, but
sorted data. For example:
l = [x for x in
(Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec
)
for _ in range(1000)] # [Jan,Jan, ..., Feb, Feb, ...]
so maybe the to_if approach will be faster if I write the case in the
best
order. Look:
l = [Jan] * 100 # to_if is in the best order for Jan
t = time(); xxx=map(to_dict,l); print time() - t # 0.5
t = time(); xxx=map(to_if,l); print time() - t # 0.5
what just using
get(key[, default])¶
Return the value for key if key is in the dictionary, else default. If
default is not given, it defaults to None, so that this method never raises
a KeyError.
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Re: embedded python on mac - linking problem
Hi, The missing symbol looks like a C++-symbol - but Python is C. Do you maybe miss the extern C declaration. I have not specified extern C as I assume it is a part of PyMODINIT_FUNC define. At least documentation says so: Note that PyMODINIT_FUNC declares the function as PyObject * return type, declares any special linkage declarations required by the platform, and for C++ declares the function as extern C. Regards, KK -- http://mail.python.org/mailman/listinfo/python-list
Introspection
I'm looking for a way to make a list of string literals in a class. Example: class A: def method(self): print 'A','BC' ExtractLiterals(A) ['A','BC'] Is this possible? Can anyone point me in the right direction? Thanks. /Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: chown'ing by script
D'Arcy J.M. Cain wrote: On Wed, 06 Jan 2010 08:58:13 -0500 Steve Holden st...@holdenweb.com wrote: Victor Subervi wrote: [Usual nonsense removed] Which, I don't doubt, could have been 2,000 lines had you bothered to Steve - any chance that you could stop replying to this idiot or at least do it privately. There's not much point to kill-filing someone if someone else is just going to repeat his posts. I think idiot's a *bit* strong, but I have to confess that even my tireless wish to evangelize Python has in Victor's case become a bit tired, so I will be happy to oblige. Victor, please refer to python-tutor for further (and more appropriate) assistance. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On Jan 5, 8:49 pm, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: (A related question - why can't I just go 'if record = method(): use (record)'. Why extra lines just to trap and assign the variable before using it?) Because that idiom is responsible for probably the most common error in C of all, at least one of the most common errors. Thank goodness Python forbids such a dangerous construct. switching = for == is the most common error in C? I can't tell if you are joking. -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On Jan 5, 10:54 pm, Benjamin Kaplan benjamin.kap...@case.edu wrote:
{41: None}[41] ?
In cases where None is a valid result, you can't use it to signal failure.
Asked and answered. You change the sentinel in .fetch to something
else.
But y'all keep on defending the language making your programming
decisions for you!
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Re: Python books, literature etc
On Wed, Jan 6, 2010 at 09:35, Shawn Milochik sh...@milochik.com wrote: Search Google. You'll find it all. Search this list's archives. This kind of thing has been discussed a thousand times. It also wouldn't hurt to brush up on this: http://catb.org/~esr/faqs/smart-questions.html Heh... I've seen that link mentioned many many times on some other lists I belong to :) But I agree. HOWEVER, that is a valid question. BUT, the answer is really up to the person asking it. For example, I too am a relative beginner with Python. Luckily I DO have at least an educational background in OOP, and at least a professional background in basic coding (some perl, BASH, etc). So I do tend to rely a lot on google when I run into a snag, THEN if that doesn't work, I come here with specific questions. FWIW, my Google searches always look something like python what I'm searching for and 99% of the time, that gives me the answers I seek. That being said, however, I also am somewhat old school and prefer to have hard copy at hand too. Sometimes, it's just that much more satisfying to have a physical book handy to look things up in. Maybe it's a comfort thing, I don't know... So in that vein, while I can't suggest any specific books, I can say this... right now, I have a copy of O'Reilly's Learning Python that I use as a reference, as well as a much older copy of the Python 2.1 Bible that I picked up almost a decade ago now the first time I messed around with Python. My personal preference, while searching Google and asking on lists like this is quick and invaluable for the real world knowledge that is shared, is to also have A: something along the lines of the Learning Foo books from O'Reilly because they tend to have lengthy explanations that I usually can understand on my own, and B: some sort of Cookbook on the topic at hand. I haven't found a Python cookbook that I like enough to buy yet, but I'm still looking. Those come in handy for simple snippets and examples when doing specific tasks. So yeah, Google and this list are certainly invaluable, but some of us actually like having the heft of a lofty tome to peruse for the answers to the mysteries of the universe. Cheers Jeff -- Charles de Gaulle - The better I get to know men, the more I find myself loving dogs. - http://www.brainyquote.com/quotes/authors/c/charles_de_gaulle.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
Phlip wrote: [...] Don't prevent me from using a technique just because others had trouble with it. I presume you also campaign against anti-lock braking systems (or at least don't use cars which have them - after all, anyone who knows how to drive should be able to brake properly, right? And even if they don't, *you* can, so you shouldn't have to pay the extra. Of course, if someone else happens to hit you because they *couldn't* drive safely you will happily give up your life). And if bar() == foo is the superior technique anyway, because the == happens in chronological and lexical order after the bar() call. That's about the most specious piece of hogwash I've seen this week. Python doesn't make any guarantees about the evaluation order of =='s operands (unlike and and or). That's cargo cult programming right there. Readability is surely the only reason to decide how to write that if, and I suspect most people would choose if foo == bar() for that reason, though the difference is slight. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On 2010-01-06, r0g aioe@technicalbloke.com wrote: NO! It's a rude way to start a sentence don't you think? No. When somebody asks a yes/no question, answering yes or no seems quite polite to me. Following the yes/no answer with an explanation of the answer is always nice, and I've little doubt that's what happened. Just because you're correcting someone doesn't mean you have to be combative and try and make them feel small. Answering a yes/no question with no doesn't seem to me to be combative if the correct answer is indeed no. But I've lost track of the post you found objectionable... -- Grant Edwards grante Yow! And then we could sit at on the hoods of cars at visi.comstop lights! -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help to pass self.count to other classes.
Steve Holden a écrit : (snip) This is untested code indeed !-) class kbInterface(object): def __init__(self): self.zxc = 0 def prompt1(self): self.count += 1 Ahem... (snip) -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
Phlip wrote: On Jan 5, 8:49 pm, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: (A related question - why can't I just go 'if record = method(): use (record)'. Why extra lines just to trap and assign the variable before using it?) Because that idiom is responsible for probably the most common error in C of all, at least one of the most common errors. Thank goodness Python forbids such a dangerous construct. switching = for == is the most common error in C? I can't tell if you are joking. Well, there's also the indenting code without surrounding it by braces error, but y'all just keep defending the approach to programming that *you* think is best. Just don't expect others to agree. The FAQ clearly documents why Python is a statement-based, and not an expression-based, language. Me, I think Guido is a pretty good language designer, and while we've had our differences I think that Python is a *much* better language than C and most others. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Introspection
Hello Martin, I'm looking for a way to make a list of string literals in a class. from inspect import getsourcelines from tokenize import generate_tokens, STRING, NUMBER def is_literal(t): return t[0] in (STRING, NUMBER) def get_lieterals(obj): lines, _ = getsourcelines(obj) readline = iter(lines).next return [t[1] for t in generate_tokens(readline) if is_literal(t)] if __name__ == __main__: class A: def f(self): print A, B print get_lieterals(A) HTH, -- Miki -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
Phlip a écrit : On Jan 5, 8:49 pm, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: (A related question - why can't I just go 'if record = method(): use (record)'. Why extra lines just to trap and assign the variable before using it?) Because that idiom is responsible for probably the most common error in C of all, at least one of the most common errors. Thank goodness Python forbids such a dangerous construct. switching = for == is the most common error in C? I can't tell if you are joking. It's at least a _very_ common error in all languages that allow this construct. In C, it's common enough to gave birth to the BestPractice you described, ie swapping operand orders in equality test to have the compiler detect the problem - at least when one of the operand is a function call expression or constant (it obviously won't 'work' when both operands are variables). Anyway: in Python, assignment is not an expression, and this isn't going to change anytime soon. -- http://mail.python.org/mailman/listinfo/python-list
Re: Dynamic text color
On Tue, 05 Jan 2010 16:54:44 -0500, Dave McCormick mackrac...@gmail.com wrote: But it is not what I am wanting. I first thought to make it look for a space but that would not work when a single character like # is to be colored if there is a string of them. Or if all of the characters between quotes are to be colored. Regular expressions are good at handling searches like: * all the characters between quotes * the two-character string do, but only if it's a complete word -John -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On 1/6/10 10:12 AM, Phlip wrote:
On Jan 5, 10:54 pm, Benjamin Kaplanbenjamin.kap...@case.edu wrote:
{41: None}[41] ?
In cases where None is a valid result, you can't use it to signal failure.
Asked and answered. You change the sentinel in .fetch to something
else.
When did I specify a sentinel value? You're saying that if None is a
valid value in the dict, you can't use slice syntax for it.
But y'all keep on defending the language making your programming
decisions for you!
Your example is the one where the language makes programming decisions
for you. Your language is deciding that if I use slice syntax, I want
the sentinel to be None. Python is deciding that unless I give it a
sentinel, there is no sentinel.
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Re: TypeError
Victor Subervi wrote:
Hi;
I get this error:
/var/www/html/angrynates.com/christians/cart/simplemail/mail.py
http://angrynates.com/christians/cart/simplemail/mail.py
153 /head
154 body'''
155 commitSale()
156 myMail()
157 print '''
commitSale = function commitSale
/var/www/html/angrynates.com/christians/cart/simplemail/mail.py
http://angrynates.com/christians/cart/simplemail/mail.py in commitSale()
98 cursor.execute('select max(ID) from %sCustomerData;' % store)
99 custID = cursor.fetchone()[0]
100 customerData(store, tmpTable, custID, patientID)
101
102 def myMail():
global customerData = function customerData, global store =
'products', tmpTable = 'tem12627568064', custID = 1, global patientID =
'None'
/var/www/html/angrynates.com/christians/cart/customerData.py
http://angrynates.com/christians/cart/customerData.py in
customerData(store='products', tmpTable='tem12627568064', custID=1,
patientID='None')
39 body
40
41 print
42 print 'h1 align=center%s Customer Data/h1' %
(store[0].upper() + store[1:])
43 cursor.execute('describe %sCustomerData' % store)
store = 'products'
ValueError: unsupported format character '(' (0x28) at index 54
args = (unsupported format character '(' (0x28) at index 54,)
Apparently that character is a file separator, which I presume is an
invisible character. I tried retyping the area in question, but with no
avail (threw same error). Please advise. Complete code follows.
Please provide the actual code (and, preferably, an easier-to-understand
traceback, like what CPython does!). What you supplied isn't runnable.
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Re: IOError - cannot create file (linux daemon-invoked script)
On Jan 5, 10:58 am, Nobody nob...@nowhere.com wrote: On Mon, 04 Jan 2010 21:30:31 -0800, cassiope wrote: One more tidbit observed: my last note, that it works when using seteuid/setegid? Well - that only applies if the daemon is running under strace (!). It fails if started directly by root, or if the strace session has ended, leaving the main body of the daemon running in its normal headless manner. I wonder if running under strace -f - might setegid/seteuid be prevented from having their normal effect? Possibly. The ptrace() syscall on which strace depends will fail if you try to trace a privileged process and you aren't root, so it's possible that a ptrace()d process will refuse to become privileged. Here, privileged includes a process which has changed any of its UIDs or GIDs (this prevents a normal user from tracing, killing, etc an otherwise privileged process which has switched to the user's UID for the time being). Thanks. I guess it's time to trim this beast to a simpler state to isolate what's going wrong. This may take awhile amidst everything else I have to be doing... -- http://mail.python.org/mailman/listinfo/python-list
Re: Introspection
On Wed, 06 Jan 2010 06:53:40 -0800, m...@infoserv.dk wrote: I'm looking for a way to make a list of string literals in a class. Example: class A: def method(self): print 'A','BC' ExtractLiterals(A) ['A','BC'] Is this possible? Can anyone point me in the right direction? class A: def extract_literals(self): return A BC.split() def method(self): print self.extract_literals() a = A() a.extract_literals() -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: TypeError
On Wed, Jan 6, 2010 at 12:29 PM, MRAB pyt...@mrabarnett.plus.com wrote:
Victor Subervi wrote:
Hi;
I get this error:
/var/www/html/angrynates.com/christians/cart/simplemail/mail.py
http://angrynates.com/christians/cart/simplemail/mail.py
153 /head
154 body'''
155 commitSale()
156 myMail()
157 print '''
commitSale = function commitSale
/var/www/html/angrynates.com/christians/cart/simplemail/mail.py
http://angrynates.com/christians/cart/simplemail/mail.py in commitSale()
98 cursor.execute('select max(ID) from %sCustomerData;' % store)
99 custID = cursor.fetchone()[0]
100 customerData(store, tmpTable, custID, patientID)
101
102 def myMail():
global customerData = function customerData, global store = 'products',
tmpTable = 'tem12627568064', custID = 1, global patientID = 'None'
/var/www/html/angrynates.com/christians/cart/customerData.py
http://angrynates.com/christians/cart/customerData.py in
customerData(store='products', tmpTable='tem12627568064', custID=1,
patientID='None')
39 body
40
41 print
42 print 'h1 align=center%s Customer Data/h1' %
(store[0].upper() + store[1:])
43 cursor.execute('describe %sCustomerData' % store)
store = 'products'
ValueError: unsupported format character '(' (0x28) at index 54
args = (unsupported format character '(' (0x28) at index 54,)
Apparently that character is a file separator, which I presume is an
invisible character. I tried retyping the area in question, but with no
avail (threw same error). Please advise. Complete code follows.
Please provide the actual code (and, preferably, an easier-to-understand
traceback, like what CPython does!). What you supplied isn't runnable.
I ended up working around this problem another way. Thanks.
beno
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Re: Need help to pass self.count to other classes.
Bruno Desthuilliers wrote: Steve Holden a écrit : (snip) This is untested code indeed !-) class kbInterface(object): def __init__(self): self.zxc = 0 def prompt1(self): self.count += 1 Ahem... (snip) Caveat emptor ... this code is worth what you paid for it :) regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: creating tar file and streaming it over HTTP?
Thanks for the tip! It doesn't change anything, though, so I've debugged this a little bit further. The problem seems to be that the receiving end (wsgi server) does not see the end of the data: socket = environ[wsgi.input] while True: sys.stderr.write(before) chunk = socket.read(4096) sys.stderr.write(after) if not chunk: sys.stderr.write(done) break sys.stderr.write(chunk) There is data from the tar file being printed, but in the end it hangs in the 'before' statement, and never gets to 'done'. I tried flushing the fileobj created by makefile(), but that doesn't seem to help. There is also no environ[CONTENT_LENGTH] that I can use to detect the end of the stream. I'm probably missing something basic here... -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
Steve Holden wrote: y'all just keep defending the approach to programming that *you* think is best. Speak for yourself... -- http://mail.python.org/mailman/listinfo/python-list
Re: lxml 2.2.4 on python3.1, Windows XP gives importerror
On 1/5/2010 1:38 AM, VYAS ASHISH M-NTB837 wrote: Dear All I have Python 3.1 installed on Windows XP and Works nice. I downloaded lxml 2.2.4 (lxml-2.2.4.win32-py3.1.exe) from pypi. When I try: from lxml import etree I get: ImportError: DLL load failed: This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem. Are you by any chance running 64-bit Python (whereas the lxml binary you have installed is 32-bit)? C: python -c import platform; print platform.architecture() -srid -- http://mail.python.org/mailman/listinfo/python-list
Re: how to change when the logging module creates the log file?
i was able to fix the exception by calling logging.shutdown() before the
call to os.remove().
However, I still think there is probably a more elegant solution.
On Wed, Jan 6, 2010 at 12:57 PM, Chris Colbert sccolb...@gmail.com wrote:
I have an application the writes to a log file when specific exceptions are
handled. However, if no exceptions are encountered, I don't want to create a
log at all.
The problem I am running into is that the stdlib logging module creates the
log file immediately upon logger instantiation.
Thus:
logger = logging.basicConifg('testlog.txt')
already creates the file 'testlog.txt'.
So, at program close, I am reading the size of the log file, and if it is
empty I remove it with os.remove(). This works fine on Linux, but throws a
permission denied exception on Windows.
There has to be a better way to do this than using a hack like that. Is
there a way to make the logging module hold-off on file creation until the
first log is generated? I could do it by wrapping logger in a class, but
that would remove the beauty of having any module import logging from the
stdlib and being able to write to the log.
Thanks for any pointers!
Chris
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getfirst and re
Hi;
I need to do something like the following:
pat = re.compile('edit[0-9]*:[0-9]*')
check = form.getfirst(pat)
(to check things like 'edit0:1') How do I do this?
TIA,
beno
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Python tk Listbox: -listvariable
Yesterday, I searched all over trying to figure out how to properly use the listvariable argument with tk's Listbox class. Unfortunately, no amount of searching (online) could come up with anything more useful than telling me the variable needed to be a list, and nothing built-in exists. I finally came across a way of using it that I consider fairly simple, and wanted to toss it out there for everyone else. One post I saw mentioned using StringVar. That just didn't work well in my head, so instead I used its parent class: Variable. Apparently, the trick is to use tuples. If I use a list, string, etc - the Listbox seems to split the content based on spaces. Not the behavior I was looking for as I have spaces in the strings I wish to display. If anyone has better suggestions, I'd love to hear them. (I thought about a ListVar class, but haven't made it much beyond the thought). Regardless, I hope the following code helps others avoid the confusion I went through. Sample code: import Tkinter, tkSimpleDialog from Tkconstants import * class ListboxTest( tkSimpleDialog.Dialog ): # def __init__( self, master, tupleItems = () ): self.myVar = Tkinter.Variable() self.myVar.set( tupleItems ) tkSimpleDialog.Dialog.__init__( self, master, Listbox testing ) # def body( self, master ): lbox = Tkinter.Listbox( master, listvariable = self.myVar ) lbox.grid( row = 0, column = 0, sticky = N + W ) self.myVar.set( self.myVar.get() + tuple( [ * Final string being added * ] ) ) print type( self.myVar.get() ), self.myVar.get() if( __main__ == __name__ ): tk = Tkinter.Tk() lt = ListboxTest( tk, tuple( [ String 1 - with some spaces, String 2 - with more spaces ] ) ) -- http://mail.python.org/mailman/listinfo/python-list
Re: getfirst and re
I need to do something like the following:
pat = re.compile('edit[0-9]*:[0-9]*')
check = form.getfirst(pat)
(to check things like 'edit0:1') How do I do this?
Well, you can do it either as
check = pat.search(string_to_search)
which is pretty plainly detailed in the help for the re module,
both under the search() function and under the 8.2.2 Matching
vs. Searching section.
Alternatively, if you plan to get the others too, you can use
fi = pat.finditer(string_to_search)
check = fi.next().group(0) # beware this may throw
# a StopIteration if there are no more matches.
which would usually be done inside a loop where the StopIteration
does the Right Thing(tm).
But if you're using it on HTML form text, regexps are usually the
wrong tool, and you should be using an HTML parser (such as
BeautifulSoup) that knows how to handle odd text and escapings
better and more robustly than regexps will.
-tkc
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Pass multidimensional array (matrix) to c function using ctypes
Hello,
I would like to pass a two dimensional array to C function in a dll. I
use ctypes to call the function.
I compile the dll with visual studio 2008 express and my C source code
looks like this.
#include stdio.h
#ifdef __cplusplus
extern C { // only need to export C interface if
// used by C++ source code
using namespace std;
#endif
__declspec(dllexport) int print(double** ptr, int ny, int nx)
{
int i, j;
for(i=0; iny; i++)
{
for(j=0; jnx; j++)
{
printf(%.3f \t, *(*(ptr+i)+j));
}
printf(\n);
}
return 0;
}
#ifdef __cplusplus
}
#endif
As you can see the function expects a doube** variable. I tried to
call this function from Python with this code.
import ctypes as ct
matrix = ct.cdll.LoadLibrary('matrix.dll')
getattr(matrix, 'print_matrix')
ptr_type = ct.c_double * 5 * 4
ptr = ptr_type()
matrix.print_matrix(ptr, ct.c_int(4), ct.c_int(5))
I expected to see a matrix showing only zeros since I can address the
single entries in Python by ptr[i][j]. Instead the interpreter returns
with the error message
WindowsError: exception: access violation reading 0x00
WARNING: Failure executing file: ctypes_matrix.py
Furthermore, I am wondering if there is a fast way to use a numpy 2D
array instead or alternatively to cast the ctypes array into a numpy
array.
Has someone an idea to help me?
Thank you very much
Daniel
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Re: getfirst and re
On Wed, Jan 6, 2010 at 1:27 PM, Tim Chase python.l...@tim.thechases.comwrote: But if you're using it on HTML form text, regexps are usually the wrong tool, and you should be using an HTML parser (such as BeautifulSoup) that knows how to handle odd text and escapings better and more robustly than regexps will. I have an automatically generated HTML form from which I need to extract data to the script which this form calls (to which the information is sent). I believe BeautifulSoup is geared to scraping pages that exist permanently on the web. By the time BeautifulSoup was called, this page would be gone. Any other ideas? TIA beno -- http://mail.python.org/mailman/listinfo/python-list
Re: getfirst and re
Victor Subervi wrote: On Wed, Jan 6, 2010 at 1:27 PM, Tim Chase python.l...@tim.thechases.comwrote: But if you're using it on HTML form text, regexps are usually the wrong tool, and you should be using an HTML parser (such as BeautifulSoup) that knows how to handle odd text and escapings better and more robustly than regexps will I have an automatically generated HTML form from which I need to extract data to the script which this form calls (to which the information is sent). I believe BeautifulSoup is geared to scraping pages that exist permanently on the web. By the time BeautifulSoup was called, this page would be gone. BeautifulSoup takes string data fed to it, and builds a structure that can be neatly navigated. That string data can come from a web page, from a disk, or even a serial port, a random-character-generator, or just from HTML that's built up in memory and never sees a network or a disk. It's worth reading its documentation[1] and trying its examples to get familiar with it. -tkc [1] http://www.crummy.com/software/BeautifulSoup/documentation.html -- http://mail.python.org/mailman/listinfo/python-list
Re: please help shrink this each_with_index() implementation
On Tue, 05 Jan 2010 12:20:58 -0800, Marco Nawijn wrote: You could use the build-in function enumerate inside a list comprehension. seq = range(5) [ (i,s) for i,s in enumerate(seq) ] [(0, 0), (1, 1), (2, 2), (3, 3), (4, 4)] Just use list(), i.e. list(enumerate(seq)). -- http://mail.python.org/mailman/listinfo/python-list
3 byte network ordered int, How To ?
For a single byte, struct.pack('B',int)
For two bytes, struct.pack('H',int)
what if I want three bytes ?
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Re: getfirst and re
On Wed, Jan 6, 2010 at 1:59 PM, Tim Chase python.l...@tim.thechases.comwrote: Victor Subervi wrote: On Wed, Jan 6, 2010 at 1:27 PM, Tim Chase python.l...@tim.thechases.com wrote: But if you're using it on HTML form text, regexps are usually the wrong tool, and you should be using an HTML parser (such as BeautifulSoup) that knows how to handle odd text and escapings better and more robustly than regexps will I have an automatically generated HTML form from which I need to extract data to the script which this form calls (to which the information is sent). I believe BeautifulSoup is geared to scraping pages that exist permanently on the web. By the time BeautifulSoup was called, this page would be gone. BeautifulSoup takes string data fed to it, and builds a structure that can be neatly navigated. That string data can come from a web page, from a disk, or even a serial port, a random-character-generator, or just from HTML that's built up in memory and never sees a network or a disk. It's worth reading its documentation[1] and trying its examples to get familiar with it. k. Thanks. beno -- http://mail.python.org/mailman/listinfo/python-list
File transfer with python
Hi there, I hope this is the rigth place, if not please, tell me which is the right dicussion place. I apologize in such case. Ok, I am trying to do a very quick application (is home based so is not a big deal...). My intention is to transfer files from one computer to another. I am using several OS (Linux and Windows basicly, but potentially in the future Mac too), and the computers won't be potentially in the same network (ok, the most times will... but there will be exceptions). My intention is to be able to transfer files from one computer to another in this environment. Looking (and surfing) at internet the only suggestion given is to use low level sockets for this file transfer. Is there another way to do it, is there any top level library that helps you to do that? That's a lot! -- http://mail.python.org/mailman/listinfo/python-list
Re: please help shrink this each_with_index() implementation
On Jan 5, 2:40 pm, Phlip phlip2...@gmail.com wrote: On Jan 5, 1:10 pm, Antoine Pitrou solip...@pitrou.net wrote: http://docs.python.org/library/functions.html Don't forget that the Python documentation is rich and structured. And good luck. Does it say how to convert a string containing either an integer representation, or something alphabetic, into an integer, or a zero, in like 1 method call? No, as he said, it only describes the most important functions. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: please help shrink this each_with_index() implementation
On Tue, 05 Jan 2010 19:46:01 -0800, alex23 wrote: They will tell me how to use except: (which is a good example why a program should not use exceptions for its normal control flow if at all possible). Really? Magic functions that coerce and eat errors are a better coding technique than exceptions and explicit handling? What kool-aid have you been drinking? Maybe he's doing it for a living? Contract programming seems to work on the basis that the ultimate requirement is for the client to hand over the money. If, at that point, the program is still full of bugs, you get to charge extra for upgrades. Writing robust software from the outset puts you at a competitive disadvantage to those who understand how the system works. -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On 1/7/2010 2:12 AM, Phlip wrote:
On Jan 5, 10:54 pm, Benjamin Kaplanbenjamin.kap...@case.edu wrote:
{41: None}[41] ?
In cases where None is a valid result, you can't use it to signal failure..
Asked and answered. You change the sentinel in .fetch to something
else.
I believe Ben Kaplan's point is that if dict slicing returns sentinel
for missing keys, the slicing syntax would be unusable to differentiate
{41: sentinel} and {}; if the default sentinel had been None, that would
make it too easy to forget to reset the sentinel and wrote a buggy code.
But y'all keep on defending the language making your programming
decisions for you!
When designing a language, there are two different ways to signal a
missing key in a dict: 1) raise an exception or 2) return a sentinel.
Both are useful for different purpose. One or the other must be the
default behavior, and the other must give way.
Python decided that the default behavior should be raising exception and
sentinel have to use the dict.get() method. Simple and clear. The other
possible behavior (i.e. slicing returns a sentinel while dict.get()
raises an exception) is arguably just as simple and just as clear; but
python doesn't do it that way. Why? Because it's part of what makes
python Python[1].
But y'all keep on defending the language making your programming
decisions for you!
Indeed, the language makes decisions for you; why would you want to use
a language that nags you for every possible different behavior? I want a
reasonable default and I want a reasonably easy way to access the
non-default behaviors.
[1] the essence of which is emboldened as the Zen, which is the broad
design guideline for both python's syntax and codes written in python.
Specifically, Errors should never pass silently because missing key
indicates a possible error and Simple is better than complex because
returning sentinel for missing keys implies the need for an interface to
change the sentinel[2].
[2] or become like Java, whose HashMap cannot reliably store null and
doesn't allow you to specify the sentinel.
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Re: Exception as the primary error handling mechanism?
On 1/7/2010 3:41 AM, Phlip wrote: Steve Holden wrote: y'all just keep defending the approach to programming that *you* think is best. Speak for yourself... Everyone speaks for themselves, is that a problem? -- http://mail.python.org/mailman/listinfo/python-list
Re: 3 byte network ordered int, How To ?
mudit tuli wrote:
For a single byte, struct.pack('B',int)
For two bytes, struct.pack('H',int)
what if I want three bytes ?
Four bytes and then discard the most-significant byte:
struct.pack('I', int)[ : -1]
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Re: subprocess.Popen does not close pipe in an error case
On Tue, 05 Jan 2010 15:50:39 -0800, Steven K. Wong wrote:
Below, I have a Python script that launches 2 child programs, prog1
and prog2, with prog1's stdout connected to prog2's stdin via a pipe.
(It's like executing prog1 | prog2 in the shell.)
If both child programs exit with 0, then the script runs to
completion. But if prog2 exits with non-0, prog1 does not exit and the
script hangs (i.e. prog1.poll() always returns None) -- unless I
uncomment the 2 lines marked by XXX to close prog1.stdout.
I was expecting that I don't have to explicitly close prog1.stdout,
whether prog2 succeeds or fails. Is the current behavior a bug in the
subprocess module or is it expected? Or am I doing something wrong?
Thanks.
import subprocess
import time
# prog1: a program that writes lots of data to the pipe
cmd = ['zcat', '--force', 'a_large_file']
prog1 = subprocess.Popen(cmd, bufsize=-1, stdout=subprocess.PIPE)
# prog2: a program that fails without reading much data from the pipe
cmd = ['python', '-c', 'import time; time.sleep(10); asdf']
prog2 = subprocess.Popen(cmd, bufsize=-1, stdin=prog1.stdout,
stdout=open('popen.out', 'w'))
I think that you should close prog1.stdout here. Otherwise, there will
be two readers on the pipe (the calling process and prog2). Even if one of
them dies, there's always the possibility that the caller might eventually
decide to read prog1.stdout itself. If you close it in the caller, when
prog2 terminates there will be no readers, and prog1 will get SIGPIPE (or
write() will fail with EPIPE if SIGPIPE is handled).
--
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Re: python xmlrpc client with ssl client certificates and standard modules
News123 wrote: This will probably work, but it requires the module M2Crypto. In order to avoid installing M2Crypto an all hosts that want to run the script I wondered, whether there is no other solution. I can do xmlrpc over ssl WITHOUT certificates with following code: [...] Please note that if you just use the stdlib it is not secure out of the box. With Python 2.6 and the ssl module you can make it so, but it requires some work on your part. See for example http://www.heikkitoivonen.net/blog/2008/10/14/ssl-in-python-26/ -- Heikki Toivonen - http://heikkitoivonen.net -- http://mail.python.org/mailman/listinfo/python-list
Re: File transfer with python
On 1/7/2010 5:00 AM, Valentin de Pablo Fouce wrote: My intention is to be able to transfer files from one computer to another in this environment. Do you have a USB flashdrive? Looking (and surfing) at internet the only suggestion given is to use low level sockets for this file transfer. Is there another way to do it, is there any top level library that helps you to do that? Networked file system (e.g. Samba/SMB), File Transfer Protocol (FTP), whatever works for you. pysamba is available from sourceforge and there is ftplib in the standard library. For most purposes though, you could just setup a network shared directory and drag and drop files from the file manager. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python books, literature etc
A good point was brought up to me privately, and I agree completely, that the OP should re-state the request with a bit more specifics... Since the OP says he is at least familiar with Python, does he need info on beginner level books that are general purpose, or is he interested in resources that are more specific (e.g. geared toward web programming, mathematical analysis, data modeling, etc) My suggestions were meant just as an example of what I use in the course of learning something at the basic and intermediate level, once it goes beyond that, it's useful to know WHAT you intend to do so you can find the right resources to go in that direction. Just want to make sure I am not misunderstood or anything :-) For what it's worth, I also tend to collect technical books for some reason... My wife is just barely tolerant of my bookshelf full of things on various computer topics, astronomy, photography, radio and antenna theory and so forth ;-) I just let her keep her shoe collection, and we have a quid pro quo. Cheers Jeff -- Mike Ditka - If God had wanted man to play soccer, he wouldn't have given us arms. - http://www.brainyquote.com/quotes/authors/m/mike_ditka.html -- http://mail.python.org/mailman/listinfo/python-list
Re: suds problem
On 2010-01-06 19:33, Fencer wrote: Hello, I just started using suds to use web services. First I tried suds with a very simple web service I had written and was running myself. That worked fine. Then I tried to use the web services provided by KEGG: http://soap.genome.jp/KEGG.wsdl But I get a SAXParseException due to a supposed mis-matched tag when I try to consume that wsdl with suds. I checked the wsdl in oxygene and it claims it's valid. What is the problem here? My test program is below and it's very simple: from suds.client import Client url = 'http://soap.genome.jp/KEGG.wsdl' client = Client(url) print client - Fencer Same problem with reactome: http://www.reactome.org:8080/caBIOWebApp/services/caBIOService?wsdl I suppose I'm mis-using suds, maybe some setting that wasn't needed for my simple web service but is needed for kegg and reactome. - Fencer -- http://mail.python.org/mailman/listinfo/python-list
Re: getfirst and re
Victor Subervi wrote: I have an automatically generated HTML form from which I need to extract data to the script which this form calls (to which the information is sent). Ideally, the script that receives the submitted fields should know how the form was generated, so it knows what fields to expect. Failing that, you should realize that getfirst() is not the only way to access the contents of a cgi.FieldStorage object. If you need to know the values of all fields whose names obey a certain pattern, I recommend you start with a list of all field names in the FieldStorage object and pick out the ones whose names obey that pattern. To get the list of field names, you should consider using the .keys() method of the FieldStorage object. -Carsten -- http://mail.python.org/mailman/listinfo/python-list
Re: getfirst and re
On Wed, Jan 6, 2010 at 3:09 PM, Carsten Haese carsten.ha...@gmail.comwrote: Victor Subervi wrote: I have an automatically generated HTML form from which I need to extract data to the script which this form calls (to which the information is sent). Ideally, the script that receives the submitted fields should know how the form was generated, so it knows what fields to expect. Failing that, you should realize that getfirst() is not the only way to access the contents of a cgi.FieldStorage object. If you need to know the values of all fields whose names obey a certain pattern, I recommend you start with a list of all field names in the FieldStorage object and pick out the ones whose names obey that pattern. To get the list of field names, you should consider using the .keys() method of the FieldStorage object. Cool. Thanks! beno -- http://mail.python.org/mailman/listinfo/python-list
Astronomy--Programs to Compute Siderial Time?
Is there a smallish Python library of basic astronomical functions? There are a number of large such libraries that are crammed with excessive functions not needed for common calculations. -- http://mail.python.org/mailman/listinfo/python-list
Need help with multiprocessing.manager and passing the manager a multiprocessing.Connection
The following code snippet is taken from the Python 2.6
multiprocessing documentation with a simple change and this change
does not work. I would like to know how to make it work or something
similar.
I want to pass a Connection object to the MathsClass.
I get the following error on Windows:
Traceback (most recent call last):
File c:\apps\python26\lib\multiprocessing\managers.py, line 214,
in serve_cl
ient
request = recv()
TypeError: Required argument 'handle' (pos 1) not found
from multiprocessing.managers import BaseManager
from multiprocessing import Pipe# I added this
class MathsClass(object):
def set(self, conn): # I added the set() function
self.conn = conn
def add(self, x, y):
return x + y
def mul(self, x, y):
return x * y
class MyManager(BaseManager):
pass
MyManager.register('Maths', MathsClass)
if __name__ == '__main__':
parent_conn, child_conn = Pipe()# I added this
manager = MyManager()
manager.start()
maths = manager.Maths()
print maths.add(4, 3) # prints 7
print maths.mul(7, 8) # prints 56
maths.set(child_conn) # I added this, error is thrown here
--
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Re: subprocess.Popen does not close pipe in an error case
On Jan 6, 10:30 am, Nobody nob...@nowhere.com wrote: I think that you should close prog1.stdout here. Otherwise, there will be two readers on the pipe (the calling process and prog2). Even if one of them dies, there's always the possibility that the caller might eventually decide to read prog1.stdout itself. If you close it in the caller, when prog2 terminates there will be no readers, and prog1 will get SIGPIPE (or write() will fail with EPIPE if SIGPIPE is handled). Thanks for raising a great point, that prog1.stdout is also readable by the calling process, not just by prog2. Therefore, I agree it makes sense to explicitly call prog1.stdout.close() in the given code (say right after the creation of prog2). Suppose now all the prog1.poll() calls/loop are replaced by a single prog1.wait(). Without the explicit prog1.stdout.close(), prog1.wait() will not return, so the calling process still hangs. Because calling prog1.wait() means that the calling process will naturally never read prog1.stdout, I would argue that prog1.wait() should close the pipe before actually waiting for prog1 to exit. Makes sense? -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On 2010-01-06, Lie Ryan lie.1...@gmail.com wrote: On 1/7/2010 3:41 AM, Phlip wrote: Steve Holden wrote: y'all just keep defending the approach to programming that *you* think is best. Speak for yourself... Everyone speaks for themselves, [...] Except for the Lorax. He speaks for the trees. -- Grant Edwards grante Yow! The SAME WAVE keeps at coming in and COLLAPSING visi.comlike a rayon MUU-MUU ... -- http://mail.python.org/mailman/listinfo/python-list
The END (of PyCon early bird registration) is NEAR!
Today is the last day of registration for PyCon 2010 at the early bird rate. Registration at the early bird rate is still good as long as it is January 6 somewhere in the world. Register now! - https://us.pycon.org/2010/register/ -- http://mail.python.org/mailman/listinfo/python-list
Re: please help shrink this each_with_index() implementation
Nobody wrote: On Tue, 05 Jan 2010 19:46:01 -0800, alex23 wrote: They will tell me how to use except: (which is a good example why a program should not use exceptions for its normal control flow if at all possible). Really? Magic functions that coerce and eat errors are a better coding technique than exceptions and explicit handling? What kool-aid have you been drinking? Maybe he's doing it for a living? Contract programming seems to work on the basis that the ultimate requirement is for the client to hand over the money. If, at that point, the program is still full of bugs, you get to charge extra for upgrades. Uh, no, right now I'm working with the long-term goal of creating useful modules that sustain us equitably. Writing robust software from the outset puts you at a competitive disadvantage to those who understand how the system works. And I, not my language, should pick and chose how to be rigorous. The language should not make the decision for me. -- http://mail.python.org/mailman/listinfo/python-list
an't start a thread Pool from another thread
Hi all, I hope someone can help me with this issue I see that i can't start a thread Pool from another thread, why? running python 2.6.4 windowsXP import multiprocessing.dummy as threads def makePool(): threads.Pool(3) makePool() import thread thread.start_new(makePool,()) Unhandled exception in thread started by function makePool at 0x011EA670 6960 -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On Jan 6, 10:23 am, Lie Ryan lie.1...@gmail.com wrote: On 1/7/2010 3:41 AM, Phlip wrote: Steve Holden wrote: y'all just keep defending the approach to programming that *you* think is best. Speak for yourself... Everyone speaks for themselves, is that a problem? Of course not. I was pointing out that Steve is telling me not to force my programming opinions on everyone... ...while defending Python enforcing programming opinions on everyone. And now, if everyone will excuse me, I have to get back to writing a unit-test-to-code ratio of 2:1. Have fun being rigorous, everyone! -- http://mail.python.org/mailman/listinfo/python-list
Mencoder and creating videos
Hello Guys, I have a multiprocessing script which downloads images from 5 urls to 5 directories(usinf multiprocess in python 2.6).The download is for 5 mins.My aim is to create a video for every minute for each directory and dump the images as the video is created. My question are , should i use *mencoder.exe * to create the videos? and how should i create the videos without interrupting the download. Thanks Aditya -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On 1/6/2010 1:20 PM, Lie Ryan wrote: Python decided that the default behavior should be raising exception and sentinel have to use the dict.get() method. Simple and clear. The other possible behavior (i.e. slicing returns a sentinel while dict.get() raises an exception) is arguably just as simple and just as clear; but python doesn't do it that way. Why? Because it's part of what makes python Python[1]. The altermatives are not quite equivalent. The current way lets one specify the sentinel whereas the alternative does not. There is hardly any reason to specify the exception. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
On Wed, 06 Jan 2010 12:39:36 -0800, Phlip wrote: And now, if everyone will excuse me, I have to get back to writing a unit-test-to-code ratio of 2:1. In my experience, that's about half as many unit-tests as needed for full code coverage for even a simple class. If you're trying to impress us, you have failed. Have fun being rigorous, everyone! You say that as if writing correct code was a bad thing. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Introspection
On Jan 6, 8:38 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Wed, 06 Jan 2010 06:53:40 -0800, m...@infoserv.dk wrote: I'm looking for a way to make a list of string literals in a class. Example: class A: def method(self): print 'A','BC' ExtractLiterals(A) ['A','BC'] Is this possible? Can anyone point me in the right direction? class A: def extract_literals(self): return A BC.split() def method(self): print self.extract_literals() a = A() a.extract_literals() -- Steven Slightly more robust than Miki's solution insofar as it doesn't require the source to exist in a .py file: import types def extract_literals(klass): for attr in (getattr(klass, item) for item in dir(klass)): if isinstance(attr, types.MethodType): for literal in attr.im_func.func_code.co_consts: if isinstance(literal, basestring): yield literal class full_of_strings(object): def a(self): return a, b, c def b(self): y, z print list(extract_literals(full_of_strings)) ['a', 'b', 'c', 'y', 'z'] print list(extract_literals(full_of_strings())) ['a', 'b', 'c', 'y', 'z'] Note that this is evil and should be avoided. -- http://mail.python.org/mailman/listinfo/python-list
Re: please help shrink this each_with_index() implementation
On Wed, 06 Jan 2010 12:12:08 -0800, Phlip wrote: And I, not my language, should pick and chose how to be rigorous. The language should not make the decision for me. All languages make that decision for you by making some thing possible and other things not. The language designer, not the programmer, decides what syntactic features to allow and disallow, what programming styles to include, and what functionality to provide as primitives. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
QDoubleValidator
Hey! I am new PyQt programmer and want to restrict users to allow only numeric values into a table and lineedit boxes. I found the QDoubleValidator class but am unsure as to how to implement it. (I am a little shaky on the concept of parent and how to define them). Any help would be much appreciated! -- http://mail.python.org/mailman/listinfo/python-list
Re: Exception as the primary error handling mechanism?
Phlip wrote: On Jan 6, 10:23 am, Lie Ryan lie.1...@gmail.com wrote: On 1/7/2010 3:41 AM, Phlip wrote: Steve Holden wrote: y'all just keep defending the approach to programming that *you* think is best. Speak for yourself... Everyone speaks for themselves, is that a problem? Of course not. I was pointing out that Steve is telling me not to force my programming opinions on everyone... ...while defending Python enforcing programming opinions on everyone. That's because Python is not a person, and Guido is a better language designer than both of us put together. No languagecan be all things to all programmers, and Python represents a set of pragmatic and useful choices. And now, if everyone will excuse me, I have to get back to writing a unit-test-to-code ratio of 2:1. Have fun being rigorous, everyone! Consider yourself excused ;-) regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS:http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
