Re: struct.Struct random access

[Tim Roberts]

castironpi <[EMAIL PROTECTED]> wrote:
>
>I'd like to seriously nominate this idea and get a considered opinion
>on it.
>
>struct.Struct lets you encode Python objects into structured memory.
>It accepts a format string, and optionally a buffer and offset to/from
>which to read/write the structure.  What do you think of random access
>to the results?  To avoid Marc's concern about meaningless anonymous
>record entries, model the constructor after 'namedtuple' type.
>
>(unproduced)
 packer= struct.Struct( 'IIIf255p', 'i1 i2 i3 afloat name' )
 packer.pack_into( buf, off, 10, 20, 30, 0.5, 'abc' )
 packer.unpack_from( buf, off, 'i3' )
>30
 packer.unpack_from( buf, off )
>( 10, 20, 30, 0.5, 'abc' )
 packer.pack_into( buf, off, 'i1', 12 )

What data type would you expect "buf" to be?  Your design requires it to be
both an input and an output parameter.  Today's "struct" converts into and
out of a string, and strings are immutable.  So, to continue with that
standard, you would have to pass a string into "pack_into" and have the
modified result returned as an output:

buf = packer.pack_into( None, 0, 10, 20, 30, 0.5, 'abc' )
buf = packer.pack_into( buf, 0, 'i1', 12 )

In the end, I'm not sure you are really saving anything.

>Even in sequential access speed benefits, by avoiding the construction
>of n-1 objects.

This is a fairly major change, because it requires a "struct.Struct" object
to maintain state, something that the "struct" module currently does not
do.

In my personal opinion, this is a rather large and confusing change, for
very little benefit.
-- 
Tim Roberts, [EMAIL PROTECTED]
Providenza & Boekelheide, Inc.
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Re: Ctypes module - looking for a way to dynamically call exported function from a set of dlls

[dudeja . rajat]

On Wed, Aug 27, 2008 at 5:20 AM, Gabriel Genellina
<[EMAIL PROTECTED]> wrote:
> En Tue, 26 Aug 2008 07:42:50 -0300, <[EMAIL PROTECTED]> escribi�:
>
>> Hi,
>>
>> I'm using the ctypes module to load my dlls.
>>
>> I have some 10 dlls the names of those are passed to a fucntion which
>> then loads the passed dll.
>>
>> Now every dll has a getversion function.
>> eg: A.dll, B.dll, C.dll are the dlls
>> and GetVersion functions are as:
>> A_getVersion(), B_getVersion(),
>> C_getVesion()
>>
>>
>>
>> The functionality I'm lookking for is that depending on the dll passed
>> the right getVersion should be passed.
>>
>> I'm able to load the all the dlls passed to the function but I'm not
>> able to call the function names dynamically
>
> Use getattr - same as with any other object.
> Suppose some_dll is your loaded DLL, then:
>
> function = getattr(some_dll, function_name)
>
> --
> Gabriel Genellina
>
> --
> http://mail.python.org/mailman/listinfo/python-list

Hi Gabriel,

Thanks for the help. That solved my problem.

-- 
Regards,
Rajat
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Re: Tkinter event loop question

[gordon]

On Aug 27, 10:42 pm, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
> so I guess the question here is from where you expect to call that
> method, and what you expect Tkinter to do when you call it...

thanks for the reply

i was planning to write a controller (as in MVC) that will instantiate
a gui class and show the ui.the gui will send user input back to the
controller which in turn will process it and send a result to the gui
to be displayed

something like

controllermodule.py

class Controller:
   def createGUI(self):
  root=Tk()
  self.mygui=uimodule.MyGUI(root)
  root.mainloop()
   def sendMessageToUI(self):
  self.mygui.displayResult(someresultValue)



i don't know if this is the right way to do this..when i call
sendMessage() it tries to call displayResult() on the gui instance
which is already in an event loop.displayResult() gets called only
after the event loop is finished(when i close gui window).

is there a way to  keep the gui window open and have the controller
send a message to the gui instance so that i can pass the processed
result value to the gui instance?

thanks
gordon


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I/O error 13 Permission denied -Cannot access file as it is used by another process.

[aditya shukla]

Hello folks,

I am creating a python script[windows vista and python2.5] which accesses
another program(prog2).I my python script i am creating a temporary file and
i write the output of prog2
in this temporary file.

temp =
tempfile.NamedTemporaryFile(suffix='_suffix',prefix='prefix_',dir='C:\\Python25')
- #this how create the temporary file ( i am not closing the temporary
file).This works fine

x= os.path.split(tn)

 y=x[1]

Now  i search for the file and then try to read this file so that i can
perform some calculations.

This step causes the problem
file=open(find_file,"rb") # find_file is the object returned after searching
the file

error mesage:

the process cannot access the file as another process because it is being
used by another program.(prog2 in this case)
i/o error 13 permission denied

Please help me on how can i fix this ? i am using os.system() in my program
to communicate with prog2

Thanks in advance

Aditya
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Re: How to ignore the first line of the text read from a file

[Chris]

On Aug 28, 6:11 am, "[EMAIL PROTECTED]"
<[EMAIL PROTECTED]> wrote:
> Hello,
>
> I am new to Python and have one simple question to which I cannot find
> a satisfactory solution.
> I want to read text line-by-line from a text file, but want to ignore
> only the first line. I know how to do it in Java (Java has been my
> primary language for the last couple of years) and following is what I
> have in Python, but I don't like it and want to learn the better way
> of doing it.
>
> file = open(fileName, 'r')
> lineNumber = 0
> for line in file:
>     if lineNumber == 0:
>         lineNumber = lineNumber + 1
>     else:
>         lineNumber = lineNumber + 1
>         print line
>
> Can anyone show me the better of doing this kind of task?
>
> Thanks in advance.

fileInput = open(filename, 'r')
for lnNum, line in enumerate(fileInput):
if not lnNum:
continue
print line
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Re: How to ignore the first line of the text read from a file

[Santiago Romero]

> I want to read text line-by-line from a text file, but want to ignore
> only the first line. I know how to do it in Java (Java has been my
> primary language for the last couple of years) and following is what I
> have in Python, but I don't like it and want to learn the better way
> of doing it.

 Why don't you read and discard the first line before processing the
rest of the file?

 file = open(filename, 'r')
 file.readline()
 for line in file: print line,

 (It works).
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Re: calling NetShareEnum win32api with ctypes

[Tim Golden]

taghi wrote:

I want to call NetShareEnum, a function from netapi32.dll


Not a straightforward answer but... are you aware that
this particular call is already wrapped by the pywin32
packages:

https://sourceforge.net/projects/pywin32/

http://timgolden.me.uk/pywin32-docs/win32net__NetShareEnum_meth.html

TJG

PS Is it me or is SourceForge's latest redesign actually
less useful than its last one?
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Re: I/O error 13 Permission denied -Cannot access file as it is used by another process.

[Tim Golden]

aditya shukla wrote:

Hello folks,

I am creating a python script[windows vista and python2.5] which 
accesses another program(prog2).I my python script i am creating a 
temporary file and i write the output of prog2

in this temporary file.

temp = 
tempfile.NamedTemporaryFile(suffix='_suffix',prefix='prefix_',dir='C:\\Python25') 
- #this how create the temporary file ( i am not closing the temporary 
file).This works fine


Why on earth are you *specifying* c:\python25 as the
directory for this file? It's automatically created
in your user-specific temp directory which has specific
permissions and is (obviously) specific to that user.
You may -- depending on your needs -- also not need the
suffix & prefix.

ie, unless you have some specific need in mind, just use:

temp = tempfile.NamedTemporaryFile ()


x= os.path.split(tn)

 y=x[1]

Now  i search for the file and then try to read this file so that i can 
perform some calculations.


This step causes the problem
file=open(find_file,"rb") # find_file is the object returned after 
searching the file


error mesage:

the process cannot access the file as another process because it is 
being used by another program.(prog2 in this case)

i/o error 13 permission denied



The main stumbling block here is that you're not posting
code you're running, but fragments of code which may or
may not exist in your source. What is tn? What have x
and y to do with anything? What is find_file? And so on.

As far as I can tell you're trying to create a temporary
file, pass its name to another process which writes to
it. You then, in the first process, read the results of
the second process. Is that right?

At the very least, please cut-and-paste a session from 
the console which is running the program so that the traceback

is clear.

Thanks
TJG
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Re: calling NetShareEnum win32api with ctypes

[Tim Golden]

taghi wrote:

I wrote this code in python 2.5:

from ctypes import *



... snip ...



netapi32=cdll.LoadLibrary('netapi32.dll')



This is your problem: netapi32 is a windows
DLL and needs to be attached as such:

 netapi32 = windll.LoadLibrary ("netapi32.dll")

or, more simply:

 netapi32 = windll.net32api

But see my other post re this function in pywin32

TJG
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Re: calling NetShareEnum win32api with ctypes

[Tim Golden]

taghi wrote:

I wrote this code in python 2.5:

from ctypes import *



... snip ...



netapi32=cdll.LoadLibrary('netapi32.dll')



This is your problem: netapi32 is a windows
DLL and needs to be attached as such:

 netapi32 = windll.LoadLibrary ("netapi32.dll")

or, more simply:

 netapi32 = windll.netapi32

But see my other post re this function in pywin32

TJG
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Re: problem with packages and path

[Marco Bizzarri]

On Wed, Aug 27, 2008 at 6:44 PM, Daniel <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I'm writing some unit tests for my python software which uses
> packages.  Here is the basic structure:
>
> mypackage
>  __init__.py
>  module1
>__init__.py
>mod1.py
>  module2
>__init__.py
>mod2.py
>  unittests
>__init__.py
>alltests.py
>test1.py
>test2.py
>
> within alltests.py I would expect to be able to "import
> mypackage.unittests.test1".  In fact within PyScripter this works as
> expected.  However, when I execute the code from the command line, I
> get the following error:
>
> ImportError: No module named mypackage.unittests.test1
>

1) What is the command you're using to run the alltest.py module?

2) what is the result of:
   - python -c "import mypackage"
  - python -c "import mypackage.unittests"

Regards
Marco



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http://iliveinpisa.blogspot.com/
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Re: calling NetShareEnum win32api with ctypes

[Gabriel Genellina]

En Thu, 28 Aug 2008 02:01:23 -0300, taghi <[EMAIL PROTECTED]> escribi�:


I want to call NetShareEnum, a function from netapi32.dll
NetShareEnum has this definition:
[...]
netapi32=cdll.LoadLibrary('netapi32.dll')
netapi32.NetShareEnum(cname, level, byref(bufptr), prefmaxlen,
byref(entriesread), byref(totalentries), byref(resume))

but I get this error:
Traceback (most recent call last):
  File "", line 1, in 
s.NetShareEnum(name, level, byref(bufptr), prefmaxlen,
entriesread, totalentries, resume)
ValueError: Procedure called with not enough arguments (28 bytes
missing) or wrong calling convention


Try with netapi32=windll.netapi32 instead

--
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Re: Syntax error in ".py" file and globals variable values not available.

[Alexis Boutillier]

Timothy Grant a écrit :

On Wed, Aug 27, 2008 at 2:49 AM, Alexis Boutillier
<[EMAIL PROTECTED]> wrote:

Hi,

I have a strange behaviour of python with pdb and import statement.
Here is the example code :

file my1.py:
import my2

file my2.py:
a=5
toto

I intentionnaly put a syntax error in file my2.py.

If I run "python -i my2.py" and run pdb I got :
NameError: name 'toto' is not defined

import pdb
pdb.pm()

-> toto

print a

5

If I run "python -i my1.py" and run pdb I got :
NameError: name 'toto' is not defined

import pdb
pdb.pm()

-> toto

print a

None

Why can't I get access to variable a in pdb when the process generating the
error came from an import statement ?

With python 2.3.5, it works fine and in the two cases I get the correct
value of 5 for variable "a".
with python 2.43,2.5.1,2.5.2, it doesn't work and I get "None" value for
variable a.

Somebody can explain me this behaviour ?


Thanks.
--
Boutillier Alexis
Methodology engineer

Arteris SA
The Network-on-Chip Company TM
www.arteris.net

6 par Ariane Immeuble Mercure
78284 Guyancourt Cedex
France
Office: (+33) 1 61 37 38 71
Fax:(+33) 1 61 37 38 41
[EMAIL PROTECTED]
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Because of the syntax error the module wasn't loaded.

What kind of behaviour would you expect on code that has been flagged
as not executable?


I got the same behaviour with :
file my2.py:
a=5
raise SystemError,""

In pdb, I can't have the value of attribute a.
So this is not linked to the fact that it is a SyntaxError or a SystemError.

I expect to be able to have the value of all attributes that have been 
used before the error occured.
This is problematic because in a more complicated code, you can't have 
the value of the attribute that was used before the error occured.
Python know that this attribute exist, it only don't have its value. 
other attribute affected are : __name__,__doc__,__file__.


--
Boutillier Alexis
Methodology engineer

Arteris SA
The Network-on-Chip Company TM
www.arteris.net

6 par Ariane Immeuble Mercure
78284 Guyancourt Cedex
France
Office: (+33) 1 61 37 38 71
Fax:(+33) 1 61 37 38 41
[EMAIL PROTECTED]
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Descriptor leak in python 2.4 subprocess module

[Michel Lespinasse]

Hi,

I hit an issue with the following python code:

try:
get_orient = subprocess.Popen (['jpegexiforient', '-n', pathfull],
   stdin = subprocess.PIPE,
   stdout = subprocess.PIPE)
orient = get_orient.communicate ()[0]
except:
orient = None

The intent of this was to read the exif orientation of a picture, or just
use None if jpegexiforient can not run.

The application worked fine on my devel machine but I noticed that on a
different host, it crashed due to running out of file descriptors.
After investigation I found out that the above code was responsible,
leaking two file descriptors per invocation if jpegexiforient is not
installed on the host.

I don't see any way to fix it in my code either, since get_orient is not
defined in the exception path, there is no way I can close its file
descriptors myself. I believe this is a bug in the subprocess module,
it should make sure to clean up after itself when getting out on the
exception path.

This is with python 2.4.4 on linux (debian etch distribution).

Hope this helps. I would prefer to be copied in any replies as I'm not
on the list (I will notice the replies after a while either way, but
it'll be faster if you can copy me).

Cheers,

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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Re: Descriptor leak in python 2.4 subprocess module

[Tim Golden]

Michel Lespinasse wrote:

Hi,

I hit an issue with the following python code:

try:
get_orient = subprocess.Popen (['jpegexiforient', '-n', pathfull],
   stdin = subprocess.PIPE,
   stdout = subprocess.PIPE)
orient = get_orient.communicate ()[0]
except:
orient = None

The intent of this was to read the exif orientation of a picture, or just
use None if jpegexiforient can not run.

The application worked fine on my devel machine but I noticed that on a
different host, it crashed due to running out of file descriptors.
After investigation I found out that the above code was responsible,
leaking two file descriptors per invocation if jpegexiforient is not
installed on the host.

I don't see any way to fix it in my code either, since get_orient is not
defined in the exception path, there is no way I can close its file
descriptors myself. I believe this is a bug in the subprocess module,
it should make sure to clean up after itself when getting out on the
exception path.



This looks like a duplicate of http://bugs.python.org/issue3210.
Can you confirm if this seems likely (and, if so, perhaps add
a note to the bug indicating that the problem is on Linux as well)?

TJG
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Re: Pythoncom and pywintypes

[Gabriel Genellina]

En Wed, 27 Aug 2008 21:17:22 -0300, Vistro <[EMAIL PROTECTED]> escribi�:


Hey, there. I've been coding in python for about three weeks now. I have
made basic games, tools to check forum PMs for me, and other general
utilities with python, but I'm now encountering problems.

http://ubuntuforums.org/archive/index.php/t-511211.html

I want to do that, and I have installed both sets needed from source  
forge,

but I always get this issue when I run the code, and there isn't a single
listing on the internet that addresses this.



Traceback (most recent call last):
  File "C:/Documents and Settings/Guest Editor/Desktop/key.py", line 3,  
in


import pythoncom
  File "C:\Python25\lib\site-packages\pythoncom.py", line 2, in 
import pywintypes
ImportError: No module named pywintypes

I've installed pythoncom right from the box. I don't know whats wrong,  
but

I'm sure it has something to do with my stupidity.


Reinstalling the pywin32 package should fix that, I presume.


BUT, here is the strangest part.

# Magic utility that "redirects" to pythoncomxx.dll
import pywintypes
pywintypes.__import_pywin32_system_module__("pythoncom", globals())


That is ALL that pythoncom.py seems to be. ALL that.

I think that it's trying to import something, THEN tell the interpreter
where it is. That seems kinda stupid.


In fact that __import_whatever function does a rather complex task, it  
must ensure that the *right* pywintypes25.dll (or pythoncom25.dll) is  
loaded, even when it's implicitely loaded.


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Re: [Q] How to ignore the first line of the text read from a file

[Ken Starks]

[EMAIL PROTECTED] wrote:

Hello,

I am new to Python and have one simple question to which I cannot find
a satisfactory solution.
I want to read text line-by-line from a text file, but want to ignore
only the first line. I know how to do it in Java (Java has been my
primary language for the last couple of years) and following is what I
have in Python, but I don't like it and want to learn the better way
of doing it.

file = open(fileName, 'r')
lineNumber = 0
for line in file:
if lineNumber == 0:
lineNumber = lineNumber + 1
else:
lineNumber = lineNumber + 1
print line

Can anyone show me the better of doing this kind of task?

Thanks in advance.



LineList=open(filename,'r').readlines()[1,]
for line in Linelist:
   blah blah
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PYTHONPATH and modules

[Juan]

Hi

I am programming a little script that makes use of a module I
developed before. The utils are inside the directory src of the
directory utils, and the package is nutum.utils. The script is in the
directory src inside the directory sysinfo, and the package is
nutum.sysinfo. Well, if not clear, this is the list of files:

ls -lR ~/workspace (imaginary output):

utils/src/nutum/__init__.py
utils/src/nutum/utils/__init__.py
utils/src/nutum/utils/general.py
utils/src/nutum/utils/elapsed_time.py
utils/src/nutum/utils/execute_command.py
utils/src/nutum/utils/size_units.py

sysinfo/src/nutum/__init__.py
sysinfo/src/nutum/sysinfo/__init__.py
sysinfo/src/nutum/sysinfo/sysinfo.py
sysinfo/src/nutum/sysinfo/modules/__init__.py
sysinfo/src/nutum/sysinfo/modules/base_module.py
sysinfo/src/nutum/sysinfo/modules/os.py

So, when from the home directory I run this command:

PYTHONPATH=workspace/utils/src/:workspace/sysinfo/src python -m
nutum.sysinfo.sysinfo --config-file /home/juan/sysinfo.config.ini

I get this output:

Traceback (most recent call last):
  File "/usr/lib/python2.5/runpy.py", line 85, in run_module
loader = get_loader(mod_name)
  File "/usr/lib/python2.5/pkgutil.py", line 456, in get_loader
return find_loader(fullname)
  File "/usr/lib/python2.5/pkgutil.py", line 466, in find_loader
for importer in iter_importers(fullname):
  File "/usr/lib/python2.5/pkgutil.py", line 422, in iter_importers
__import__(pkg)
ImportError: No module named sysinfo

Also, if I run this similar command:

PYTHONPATH=workspace/utils/src/:workspace/sysinfo/src python workspace/
sysinfo/src/nutum/sysinfo/sysinfo.py --config-file /home/juan/
sysinfo.config.ini

The output is this:

No module named sysinfo.modules.os
Traceback (most recent call last):
  File "workspace/sysinfo/src/nutum/sysinfo/sysinfo.py", line 156, in

classinstance = get_class(class_name)()
  File "/home/juan/workspace/utils/src/nutum/utils/general.py", line
44, in get_class
aClass = get_func(fullClassName)
  File "/home/juan/workspace/utils/src/nutum/utils/general.py", line
27, in get_func
aMod = get_mod(modPath)
  File "/home/juan/workspace/utils/src/nutum/utils/general.py", line
14, in get_mod
aMod = __import__(modulePath, globals(), locals(), [''])
ImportError: No module named sysinfo.modules.os

Why this does happens? Why Python does not find the modules if they
are already in the path? Why (in the second example) tries to find the
module "sysinfo.modules.os" when I am really importing the module
"nutum.sysinfo.modules.os"

Thanks in advance.
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Re: [Q] How to ignore the first line of the text read from a file

[Paul Rubin]

Ken Starks <[EMAIL PROTECTED]> writes:
> LineList=open(filename,'r').readlines()[1,]

You don't want to do that if the file is very large.  Also,
you meant [1:] rather than [1,]

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Re: How to ignore the first line of the text read from a file

[Chris]

On Aug 28, 11:53 am, Ken Starks <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] wrote:
> > Hello,
>
> > I am new to Python and have one simple question to which I cannot find
> > a satisfactory solution.
> > I want to read text line-by-line from a text file, but want to ignore
> > only the first line. I know how to do it in Java (Java has been my
> > primary language for the last couple of years) and following is what I
> > have in Python, but I don't like it and want to learn the better way
> > of doing it.
>
> > file = open(fileName, 'r')
> > lineNumber = 0
> > for line in file:
> >     if lineNumber == 0:
> >         lineNumber = lineNumber + 1
> >     else:
> >         lineNumber = lineNumber + 1
> >         print line
>
> > Can anyone show me the better of doing this kind of task?
>
> > Thanks in advance.
>
> LineList=open(filename,'r').readlines()[1,]
> for line in Linelist:
>     blah blah

That's bad practice as you load the entire file in memory first as
well as it will result in a type error (should be '.readlines()[1:]')
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filter in for loop

[GHZ]

I would like to say something like:

for x in l if :


e.g.

for filename in os.listdir(DIR) if filename[-4:] == '.xml':



instead of having to say:

for filename in os.listdir(DIR):
if filename[-4:] == '.xml':


or

for filename in (f for f in os.listdir(DIR) if f[-4] == '.xml'):



is there a shortcut I'm missing?
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Re: filter in for loop

[Bruno Desthuilliers]

GHZ a écrit :

I would like to say something like:

for x in l if :


e.g.

for filename in os.listdir(DIR) if filename[-4:] == '.xml':



instead of having to say:

for filename in os.listdir(DIR):
if filename[-4:] == '.xml':


or

for filename in (f for f in os.listdir(DIR) if f[-4] == '.xml'):



is there a shortcut I'm missing?


Not AFAIK, and I sometimes regret it - but the first alternative is good 
enough IMHO.



I'd rather use os.path.splitext or str.endswith than subscript, but YMMV.

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Re: filter in for loop

[Chris]

On Aug 28, 12:20 pm, GHZ <[EMAIL PROTECTED]> wrote:
> I would like to say something like:
>
> for x in l if :
>     
>
> e.g.
>
> for filename in os.listdir(DIR) if filename[-4:] == '.xml':
>     
>
> instead of having to say:
>
> for filename in os.listdir(DIR):
>     if filename[-4:] == '.xml':
>         
>
> or
>
> for filename in (f for f in os.listdir(DIR) if f[-4] == '.xml'):
>     
>
> is there a shortcut I'm missing?

from glob import glob
from os import path
DIR = 'PathToFiles'
EXT = '*.xml'

for filename in glob(path.join(DIR, EXT)):
print filename

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Re: filter in for loop

[Timo]

On 28 elo, 13:20, GHZ <[EMAIL PROTECTED]> wrote:

>
> is there a shortcut I'm missing?

(Adding to Bruno's comment)

This kind of style provides a reusable filter/generator-function and
as a bonus, the for-loop becomes easier to understand.

from os.path import abspath
from glob import iglob

def ipathnames(pattern):
return (abspath(n) for n in iglob(pattern))

for xmlfile in ipathnames('*.xml'):


-- timo
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Re: Python sockets UDP broadcast multicast question??

[Francesco Bochicchio]

On 28 Ago, 08:09, inorlando <[EMAIL PROTECTED]> wrote:
> Hi all,
>
> I have a question about python and sockets , UDP datagram in
> particular. I'm new to socket programming so please bare with me.
>
> I am trying to write a simple application that broadcast files to
> another computer on the same network/subnet but I do not want the
> receiver computer to have to respond, I only want it to receive the
> packet.
>
> So this was simple enough, but my problem is this when I send a file
> that is say larger then 100K the receiver is not able to keep up with
> the packets as they arrive. I get say 60 or so then the rest are
> ignored.
>
> I have tried a couple of different approaches like threading and
> queuing,  but all ultimately have the same problem.
>
> So my question is how can I receive a continuous stream of UDP packets
> to some kind of buffer for processing with out losing packets?
>
> Thank you for any help or guidance that you provide.
>
> - InOrlando

The UDP protocol is defined 'unreliable' because it cannot guarantee
in all conditions
the delivery of all packets in the correct sequence. This means than
in specific conditions,  e.g.
when the network or one of the communicating computers is overloaded,
you can loose packets or
receive them in the wrong order.

So, first of all, if you cannon tolerate packet loss, consider
switching the protocol to TCP.
If you cannot change protocol (maybe because TCP has no multicast),
then try to reduce the load on the
computer and the network, e.g. by inserting a delay between two packet
transmissions. But remember that
this only reduce, does not cancel, the possibility of packet loss or
packet mis-ordering.

Of course, it could be a bug in your program, in which case none of
the above matters ;)

Ciao
-
FB

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Re: Function References

[Lie]

On Aug 1, 6:35 am, "Diez B. Roggisch" <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] schrieb:
>
> > On Jul 31, 10:47 am, "Diez B. Roggisch" <[EMAIL PROTECTED]> wrote:
> >> I take the freedom to do so as I see fit - this is usenet...
>
> > Fine, then keep beating a dead horse by replying to this thread with
> > things that do nobody any good. It seems like there are a lot better
> > way to waste time, though.
>
> You mean like trying to wrap ones head around the rather simple Python C
> API, not getting a callback mechanism implemented?
>
> For the record: I've wrapped C-libs myself, including callbacks. Been
> there, done that, discovered (years later) cytpes, been there for good.
>
> > The Python/C API can get me back further without reliance on third-
> > party libraries than ctypes.
>
> You don't consider your own library a third party lib? And unless you're
> wrapping C++, you're opinion is as uninformed as it is wrong.
>
> > It also isn't subject to the quirks that
> > ctypes is on platforms other than Windows (the target application runs
> > on Windows, Mac, and eventually Linux once the original distributor
> > has drivers for the device). I'm not even sure ctypes could load the
> > lib/driver the distributor packaged.
>
> Oh please. I'm 98% working on linux & osx. ctypes does a great job on
> these platforms.
>
> Regarding your objections I can only say: whatever the python runtime
> can load because of the underlying ld, ctypes can load. simply because
> they are the same. If *that* was the actual cause of problems, we
> wouldn't even talk about callbacks here.
>
> > So really, I appreciate the option in ctypes, it's good stuff. But
> > it's not for this project.
>
> Stop finding lame excuses for not wanting to ditch the work you've done
> in favor of a easier solution. You like your code, you want to keep it,
> you want to discover the intricasies of the Python C API? Be my guest.
>
> But stop embarassing yourself inventing reasons like licensing or linker
> problems you don't support with any facts whatsoever.
>
> > Once again, the original question stands for anyone who has experience
> > with the Python/C API callbacks.
>
> You know what? Just for the fun of it, I'll take a stab at it.
>
>   It's easy: Create a "proxy-function" that matches the prototype of the
> c8allback which converts the passed arguments to python values using the
> C-api. Then call the registered python function using
> PyObject_CallFunction.
>
> Convert the return-value back to C, and return it.
>
> Make the function get the PyObject* for the call fetch from a global
> variable you set in the register-callback function, where you also
> register the proxy-function for the first time, or de-register if the
> passed value is None or such.
>
> Have fun.
>
> Diez

Zen's lesson for today:
THOU SHALT NOT MESS WITH ANY PYTHON'S SEMI-GODS, DEMI-GODS, AND
PYTHON'S GOD.

You're lucky Diez still want to help you with your attitude like that.
May I remind you that we here helps you for free in our free time, be
rude, especially to a frequent member, and you'll get what you deserve.
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Re: Function References

[Diez B. Roggisch]

> Zen's lesson for today:
> THOU SHALT NOT MESS WITH ANY PYTHON'S SEMI-GODS, DEMI-GODS, AND
> PYTHON'S GOD.
> 
> You're lucky Diez still want to help you with your attitude like that.
> May I remind you that we here helps you for free in our free time, be
> rude, especially to a frequent member, and you'll get what you deserve.

Thanks Lie, but I certainly don't consider myself being part of Python's
olymp... :) Others here of course are, and a friendly and open attitude
from everybody sure helps keeping this institution helpful.

This goes also for frequent members - and I do include myself here, as I
*sometimes* forget that myself, but try hard not to.

Diez
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Tkinter tkMessageBox problem - message box is displayed with an additional window

[dudeja . rajat]

Hi,
I'm working on Windows Platform

I'm facing some problem with the tkMessageBox. My code is as below:

import tkMessageBox
import Tix
from Tkinter import *

if len(installedLibPath) != len(listOfLibraries):
if tkMessageBox.askyesno("Question", \
 type='yesno', icon='warning', \
 message="Some of the libraries are
not installed. Do you wish to continue with the remaining?"):
myRoot = Tix.Tk()
myAppGUIObject = myAppGUI(myRoot)#Class for my GUI
myRoot.mainloop()
else:
sys.exit(0)


The Message Box is called before the Tix.Tk mainloop(). The problems
are as under :

1. Since the message box is displayed before the mainloop() is
started, the message box is displayed with another window that is
blank. This should not be displayed.

2. As a results of this messagebox (called before the mainloop) the
original Gui started by mainloop doesnot work as desired. Some of the
checkbuttons are displayed as unset (i.e un-ticked). These
checkbuttons used to be set at initialization before I stared using
this messagebox.


Please help.

Thanks and regards,
Rajat
-- 
Regrads,
Rajat
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Re: PYTHONPATH and modules

[Bruno Desthuilliers]

Juan a écrit :

Hi

I am programming a little script that makes use of a module I
developed before. The utils are inside the directory src of the
directory utils, and the package is nutum.utils. The script is in the
directory src inside the directory sysinfo, and the package is
nutum.sysinfo.


Won't work, cf below.


Well, if not clear, this is the list of files:

ls -lR ~/workspace (imaginary output):

utils/src/nutum/__init__.py
utils/src/nutum/utils/__init__.py
utils/src/nutum/utils/general.py
utils/src/nutum/utils/elapsed_time.py
utils/src/nutum/utils/execute_command.py
utils/src/nutum/utils/size_units.py

sysinfo/src/nutum/__init__.py
sysinfo/src/nutum/sysinfo/__init__.py
sysinfo/src/nutum/sysinfo/sysinfo.py
sysinfo/src/nutum/sysinfo/modules/__init__.py
sysinfo/src/nutum/sysinfo/modules/base_module.py
sysinfo/src/nutum/sysinfo/modules/os.py


A Python package is a filesystem directory with an __init__.py file in 
it. In your above layout, you have two *distinct, unrelated* packages 
both named nutum. The first found in sys.path will shadow the second.


You either need to rename one, or "refactor" your layout to have utils 
and sysinfo under the same root package, ie:


workspace/src/nutum/__init__.py
workspace/src/nutum/utils/__init__.py
workspace/src/nutum/utils/general.py
workspace/src/nutum/utils/elapsed_time.py
workspace/src/nutum/utils/execute_command.py
workspace/src/nutum/utils/size_units.py
workspace/src/nutum/sysinfo/__init__.py
workspace/src/nutum/sysinfo/sysinfo.py
workspace/src/nutum/sysinfo/modules/__init__.py
workspace/src/nutum/sysinfo/modules/base_module.py
workspace/src/nutum/sysinfo/modules/os.py

HTH
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ANN: Leo 4.5 rc1 released

[Edward K Ream]

Leo 4.5 rc1 is now available at:
http://sourceforge.net/project/showfiles.php?group_id=3458&package_id=29106

Leo 4.5 contains many important new features.  See below for details.

Leo is a text editor, data organizer, project manager and much more. See:
http://webpages.charter.net/edreamleo/intro.html

The highlights of Leo 4.5:
--

- Full support for @shadow files in Leo's core.
- Major improvements to Leo's key binding code.
- The beginning of usable vim-like bindings.
- uA's may now be associated with vnodes in @thin and @shadow files.
- Several magor reorganizations of Leo's code:
  including sax-based parsing, support for the Graph world (unified nodes),
  and simplified drawing code.
- Leo is now an installable package.
- Prepared code to be ready for Python 3.0.
- Many small improvements and bug fixes.

Links:
--
Leo:  http://webpages.charter.net/edreamleo/front.html
Forum:http://groups.google.com/group/leo-editor
Download: http://sourceforge.net/project/showfiles.php?group_id=3458
Bzr:  http://code.launchpad.net/leo-editor/
Quotes:   http://webpages.charter.net/edreamleo/testimonials.html

Edward K. Ream   email:  [EMAIL PROTECTED]
Leo: http://webpages.charter.net/edreamleo/front.html



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Re: How to ignore the first line of the text read from a file

[rurpy]

On Aug 27, 11:12 pm, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote:
> On Wed, 27 Aug 2008 21:11:26 -0700, [EMAIL PROTECTED] wrote:
> > I want to read text line-by-line from a text file, but want to ignore
> > only the first line. I know how to do it in Java (Java has been my
> > primary language for the last couple of years) and following is what I
> > have in Python, but I don't like it and want to learn the better way of
> > doing it.
>
> > file = open(fileName, 'r')
> > lineNumber = 0
> > for line in file:
> > if lineNumber == 0:
> > lineNumber = lineNumber + 1
> > else:
> > lineNumber = lineNumber + 1
> > print line
>
> > Can anyone show me the better of doing this kind of task?
>
> input_file = open(filename)
> lines = iter(input_file)
> lines.next()# Skip line.
> for line in lines:
> print line
> input_file.close()
>
> Ciao,
> Marc 'BlackJack' Rintsch

A file object is its own iterator so you can
do more simply:

input_file = open(filename)
input_file.next()# Skip line.
for line in input_file:
print line,
input_file.close()

Since the line read includes the terminating
EOL character(s), print it with a "print ... ,"
to avoid adding an additional EOL.

If the OP needs line numbers elsewhere in the
code something like the following would work.

infile = open(fileName, 'r')
for lineNumber, line in enumerate (infile):
# enumerate returns numbers starting with 0.
if lineNumber == 0: continue
print line,
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Re: GUI programming with python

[Bruno Desthuilliers]

zamil a écrit :

Hello Everyone

It's my very first email to this group. i am a beginner programmer of
python. it it possible to build Desktop application using python.


Yes.


Which IDE should i use for this purpose?


I suspect you are confusing "IDE" with "GUI builder". FWIW, you don't 
*need* any IDE nor GUI builder - a decent code editor is enough. Now if 
you really want a GUI builder, you'll have to choose one that's tied to 
your GUI toolkit and that run on your platform.

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Re: How to ignore the first line of the text read from a file

[Paul Rubin]

[EMAIL PROTECTED] writes:
> If the OP needs line numbers elsewhere in the
> code something like the following would work.
> 
> infile = open(fileName, 'r')
> for lineNumber, line in enumerate (infile):
> # enumerate returns numbers starting with 0.
> if lineNumber == 0: continue
> print line,

This also seems like a good time to mention (untested):

   from itertools import islice

   for line in islice(infile, 1, None):
  print line,
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Re: Process "Killed"

[Matt Nordhoff]

dieter wrote:
> Hi,
> 
> Overview
> ===
> 
> I'm doing some simple file manipulation work and the process gets
> "Killed" everytime I run it. No traceback, no segfault... just the
> word "Killed" in the bash shell and the process ends. The first few
> batch runs would only succeed with one or two files being processed
> (out of 60) before the process was "Killed". Now it makes no
> successful progress at all. Just a little processing then "Killed".

That isn't a Python thing. Run "sleep 60" in one shell, then "kill -9"
the process in another shell, and you'll get the same message.

I know my shared web host has a daemon that does that to processes that
consume too many resources.

Wait a minute. If you ran this multiple times, won't it have removed the
first two lines from the first files multiple times, deleting some data
you actually care about? I hope you have backups...

> Question
> ===
> 
> Any Ideas? Is there a buffer limitation? Do you think it could be the
> filesystem?
> Any suggestions appreciated Thanks.
> 
> 
> The code I'm running:
> ==
> 
> from glob import glob
> 
> def manipFiles():
> filePathList = glob('/data/ascii/*.dat')

If that dir is very large, that could be slow. Both because glob will
run a regexp over every filename, and because it will return a list of
every file that matches.

If you have Python 2.5, you could use glob.iglob() instead of
glob.glob(), which returns an iterator instead of a list.

> for filePath in filePathList:
> f = open(filePath, 'r')
> lines = f.readlines()[2:]

This reads the entire file into memory. Even better, I bet slicing
copies the list object temporarily, before the first one is destroyed.

> f.close()
> f = open(filePath, 'w')
> f.writelines(lines)
> f.close()
> print file

This is unrelated, but "print file" will just say "",
because it's the name of a built-in object, and you didn't assign to it
(which you shouldn't anyway).


Actually, if you *only* ran that exact code, it should exit almost
instantly, since it does one import, defines a function, but doesn't
actually call anything. ;-)

> Sample lines in File:
> 
> 
> # time, ap, bp, as, bs, price, vol, size, seq, isUpLast, isUpVol,
> isCancel
> 
> 1062993789 0 0 0 0 1022.75 1 1 0 1 0 0
> 1073883668 1120 1119.75 28 33 0 0 0 0 0 0 0
> 
> 
> Other Info
> 
> 
> - The file sizes range from 76 Kb to 146 Mb
> - I'm running on a Gentoo Linux OS
> - The filesystem is partitioned and using: XFS for the data
> repository, Reiser3 for all else.

How about this version? (note: untested)

import glob
import os

def manipFiles():
# If you don't have Python 2.5, use "glob.glob" instead.
filePaths = glob.iglob('/data/ascii/*.dat')
for filePath in filePaths:
print filePath
fin = open(filePath, 'rb')
fout = open(filePath + '.out', 'wb')
# Discard two lines
fin.next(); fin.next()
fout.writelines(fin)
fin.close()
fout.close()
os.rename(filePath + '.out', filePath)

I don't know how light it will be on CPU, but it should use very little
memory (unless you have some extremely long lines, I guess). You could
write a version that just used .read() and .write() in chunks

Also, it temporarily duplicates "whatever.dat" to "whatever.dat.out",
and if "whatever.dat.out" already exists, it will blindly overwrite it.

Also, if this is anything but a one-shot script, you should use
"try...finally" statements to make sure the file objects get closed (or,
in Python 2.5, the "with" statement).
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Re: python on Mac

[Lou Pecora]

In article <[EMAIL PROTECTED]>,
 [EMAIL PROTECTED] wrote:

> Hi All.
> I'm really new in the python world, so, sorry if my question is particulary
> stupid.
> I've just installed on my system (Mac OS X 10.4 PPC) the python version
> 2.5.2 and all works fine.
> My next step is to install the version 3.0 (when available). I've read
> somewhere that this version will break the backward compatibility with the
> 2.x series. I know that several Mac apps (such as Xcode developement
> environment) use python for its internal functionalities. Now, my question
> is: what will appen to the Mac apps if I install the version 3.0 of python?
> Is it safe to install this version without to compromise the behaviour of
> the system?
> 
> Thanks in advance for any answer and, again, sorry if my question is
> particulary stupid, I will learn with time.
> 
> Luca.

The standard Python installs that I have put the new python in the 
directory /Library/Frameworks/Python.framework/Versions/Current/   and 
the additional packages in some subdirectory of that one.

The Apple installed Python is in 
/System/Library/Frameworks/Python.framework/Versions/Current/

DO NOT TOUCH that one.  Just leave it alone.  You can set your 
.bash_profile path to make sure your Python is used when you run your 
scripts.  This shouldn't affect the Apple Python.  Basically, the 
directories /usr/local/:/usr/local/bin/ should come *before* the system 
/bin directories.  So your .bash_profile should have something like this 
line in it:

PATH="/usr/local/:/usr/local/bin/:${PATH}"
export PATH

Bottom line:  your installs and Apples' Python are separate and that's 
how it should be.  

Hope that helps.  Others: please correct if I am wrong. Thanks.

-- 
-- Lou Pecora
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PyImport_ImportModule deadlocks

[[EMAIL PROTECTED]]

Hey all,

I have an embedded Python shell and everything works fine, however, in
my stdout catcher (in C to grab tracebacks) for some reason when I do
a :

PyImport_ImportModule( "sys" )

It deadlocks the process, is there a need for me to acquire locks
inside of my stdout catching function before calling that import?
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Re: Multiple values for one key

[Maric Michaud]

Le Thursday 28 August 2008 03:43:16 norseman, vous avez écrit :
> Terry Reedy wrote:
> > Ron Brennan wrote:
> >> Hello,
> >>
> >>
> >> How would I create a dictionary that contains multiple values for one
> >> key.
> >
> > Make the value a collection object (set or list if you plan to add and
> > delete).
> >
> >>  I'd also like the key to be able to have duplicate entries.
> >
> > Dict keys must be hashable and unique.
> >
> > tjr
> >
> > --
> > http://mail.python.org/mailman/listinfo/python-list
>
> 
> First part I understand, second is still giving me a problem.
>
> For some reason I still want keys to be dbf column headers.
> like:
>
> name:address:zip so forth
>  --- --- --
> guy: unknown:0
> girl: 123 tiny street:12345
> boy:321 here:3
> gal:999 over there: 5
> so forth
>
> Thus one key has many values. And you can then index on whatever key(s)
> you wish - name,zip...
>
> With billions plus records, trying to put a unique key on each entry
> seems to preclude the need for a dictionary, just use the entries.
> (Format to SDF and index on substr(line,1,24)+substr(line,48,+5) etc..)
>name+ zip
> OK - I know I missed the whole concept of a Python Dictionary. I haven't
> read anything as yet that gives a clear picture of what it is and what
> it is for.  Please, classroom concepts usually consist of a handful of
> objects. I have files here that takes up multiple DVDs each, AFTER a 15
> to 1 compression. 3 bytes per pixel. I need to work with them. Things
> like changing geobase projections and cookie cutting based on real world
> coordinates and modifying the lumens and so forth. Based on what I've
> read, the Python Dictionary concept flat will not work for such as this.
> Yes - the example is overkill. But in my world it is reality. I deal
> with sizeable things. Not all are raster. Most all are binary!  Things
> that work on massive text files - like banking and mortgage - simply
> don't work here. There are seldom 'lines'. There are always bytes. Lots
> of bytes. Things that form a group are not necessarily stored sequentially.
>
> Back to What Is A Python Dictionary: Somebody please enlighten me.
>


Disctionaries are hash tables with a unique key and constant time lookup. What 
you want could be implemented as a complex data structures with as many dict 
as needed keys, but it seems you really want a relational table and a rdbms. 
This is exactly what they are for. A short example with the new python2.5 
sqlite package :

>>>[107]: import sqlite3

>>>[108]: from string import letters

>>>[109]: db = sqlite3.connect(':memory:')

>>>[110]: db.execute("create table 'table1' ('name' text(20), 'address' 
text(100), primary key ('name', 'address'))")
...[110]: 

>>>[111]: db.executemany("insert into 'table1' values (?, ?)", 
((letters[i%len(letters)]*i, "%d street" % i) for i in range(1000))).rowcount
...[111]: 1000

>>>[112]: for i in db.execute("select * from 'table1' where address 
like '99 %'") : print i
   .:
(u'VVV',
 
u'99 street')

>>>[113]: for i in db.execute("select * from 'table1' where name 
like '___'") : print i
   .:
(u'ddd', u'3 street')

>>>[114]: db.execute("insert into 'table1' values (?, ?)", ('ddd', '4 
street')).rowcount
...[114]: 1

>>>[115]: for i in db.execute("select * from 'table1' where name 
like '___'") : print i
   .:
(u'ddd', u'3 street')
(u'ddd', u'4 street')

>>>[116]: db.execute("insert into 'table1' values (?, ?)", ('ddd', '4 
street')).rowcount
---
IntegrityErrorTraceback (most recent call last)

/home/maric/ in ()

IntegrityError: columns name, address are not unique



>
> Steve
> [EMAIL PROTECTED]
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_

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Re: List of modules available for import inside Python?

[pruebauno]

On Aug 28, 12:21 am, ssecorp <[EMAIL PROTECTED]> wrote:
> Is there a way to view all the modules I have available for import
> from within Python?
> Like writing in the interpreter:
> import.modules
>
> Also, is there anything like Cpan for Python?

Isn't the most obvious answer to the first question this link?

http://docs.python.org/modindex.html
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Re: Tkinter tkMessageBox problem - message box is displayed with an additional window

[Guilherme Polo]

On Thu, Aug 28, 2008 at 10:29 AM,  <[EMAIL PROTECTED]> wrote:
> Hi,
> I'm working on Windows Platform
>
> I'm facing some problem with the tkMessageBox. My code is as below:
>
> import tkMessageBox
> import Tix
> from Tkinter import *
>
> if len(installedLibPath) != len(listOfLibraries):
>if tkMessageBox.askyesno("Question", \
> type='yesno', icon='warning', \
> message="Some of the libraries are
> not installed. Do you wish to continue with the remaining?"):
>myRoot = Tix.Tk()
>myAppGUIObject = myAppGUI(myRoot)#Class for my GUI
>myRoot.mainloop()
> else:
>sys.exit(0)
>

It is good to post a short code sample that demonstrates the problem,
but it has to run by itself at least.

>
> The Message Box is called before the Tix.Tk mainloop(). The problems
> are as under :
>
> 1. Since the message box is displayed before the mainloop() is
> started, the message box is displayed with another window that is
> blank. This should not be displayed.
>
> 2. As a results of this messagebox (called before the mainloop) the
> original Gui started by mainloop doesnot work as desired. Some of the
> checkbuttons are displayed as unset (i.e un-ticked). These
> checkbuttons used to be set at initialization before I stared using
> this messagebox.

tkMessageBox blocks till you finish it, maybe that is what is causing
your problem but it is hard to tell what you are doing wrong in that
myAppGui without seeing it (preferably reduced code demonstrating the
problem).

Now.. an attempt to solve your problem. Tk always has a root window
going on, so that "another window" is inevitable, but you can hide and
show it again when needed. You could do something like this:

import tkMessageBox
import Tkinter

class App(object):
def __init__(self, master):
self.master = master
print "tkMessageBox is gone now"

root = Tkinter.Tk()
root.withdraw()
tkMessageBox.askyesno("Question", message="Do you use Python?",
type='yesno', icon='warning', master=root)
root.deiconify()

app = App(root)
root.mainloop()

>
>
> Please help.
>
> Thanks and regards,
> Rajat
> --
> Regrads,
> Rajat
> --
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>



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Re: filter in for loop

[Jerry Hill]

On Thu, Aug 28, 2008 at 6:20 AM, GHZ <[EMAIL PROTECTED]> wrote:
> is there a shortcut I'm missing?

Well, there's another way to do it, using the filter built in function:

for filename in filter(lambda f:f.endswith('.xml'), os.listdir('.')):
print filename

You can do the same thing with itertools.ifilter if you need to deal
with arbitrary iterables.  I think your first example of:

for filename in os.listdir('.'):
   if filename.endswith('.xml'):
   

Is the most readable though.

-- 
Jerry
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Python svn bindings for Subversion?

[Mike B]

I'm trying to get Subversion 'hook scripts' working on an Ubuntu box and the
following fails.

from svn import fs, repos, core, delta

As far as I can tell there are two Python Subversion libraries, 'pysvn' and
'svn':
'pysvn' from http://pysvn.tigris.org/ appears to be a client side interface and
isn't what I need.
'svn' appears to be a SWIG wrapper and could be what I'm looking for, but I
cannot find it anywhere.

Can anyone point me in the right direction.

Thanks

Mike

 
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cannot find object instance

[jimgardener]

hi,
i am a python newbie..while trying out some message passing between
two object instances i came across a problem
moduleA.py

import moduleB
class MyClassA:
def __init__(self):
self.age=0
self.address=''
def createClassB(self):
self.objB=moduleB.MyClassB()
def validate(self,age,address):
if(age >= 100 or address==''):
self.age=20;
self.address="Broadway,NewYork"
self.objB.display(self.age,self.address)
def callB(self):
self.objB.execute()

if __name__ == "__main__":
objA=MyClassA()
objA.createClassB()
objA.callB()

moduleB.py
--
import moduleA

class MyClassB:
def __init__(self):
self.createA()
def createA(self):
self.objA=moduleA.MyClassA()
def execute(self):
self.objA.validate(111,'')
def display(self,age,address):
print 'displaying:',str(age),address

when i run the code i get a message
AttributeError: MyClassA instance has no attribute 'objB'

Do i have to put a placeholder for objB in __init__ of MyClassA ?
is that why i get this error?someone please tell me how i can solve
this? I tried to put self.objB=None but it didn't work..(i was
thinking of java style objB=NULL )

please help
thanks
jim
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Re: Identifying the start of good data in a list

[Gerard flanagan]

George Sakkis wrote:

On Aug 27, 3:00 pm, Gerard flanagan <[EMAIL PROTECTED]> wrote:


[EMAIL PROTECTED] wrote:

I have a list that starts with zeros, has sporadic data, and then has
good data. I define the point at  which the data turns good to be the
first index with a non-zero entry that is followed by at least 4
consecutive non-zero data items (i.e. a week's worth of non-zero
data). For example, if my list is [0, 0, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8,
9], I would define the point at which data turns good to be 4 (1
followed by 2, 3, 4, 5).
I have a simple algorithm to identify this changepoint, but it looks
crude: is there a cleaner, more elegant way to do this?
flag = True
i=-1
j=0
while flag and i < len(retHist)-1:
i += 1
if retHist[i] == 0:
j = 0
else:
j += 1
if j == 5:
flag = False
del retHist[:i-4]
Thanks in advance for your help
Thomas Philips

data = [0, 0, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

def itergood(indata):
 indata = iter(indata)
 buf = []
 while len(buf) < 4:
 buf.append(indata.next())
 if buf[-1] == 0:
 buf[:] = []
 for x in buf:
 yield x
 for x in indata:
 yield x

for d in itergood(data):
 print d


This seems the most efficient so far for arbitrary iterables. With a
few micro-optimizations it becomes:

from itertools import chain

def itergood(indata, good_ones=4):
indata = iter(indata); get_next = indata.next
buf = []; append = buf.append
while len(buf) < good_ones:
next = get_next()
if next: append(next)
else: del buf[:]
return chain(buf, indata)

$ python -m timeit -s "x = 1000*[0, 0, 0, 1, 2, 3] + [1,2,3,4]; from
itergood import itergood" "list(itergood(x))"
100 loops, best of 3: 3.09 msec per loop

And with Psyco enabled:
$ python -m timeit -s "x = 1000*[0, 0, 0, 1, 2, 3] + [1,2,3,4]; from
itergood import itergood" "list(itergood(x))"
1000 loops, best of 3: 466 usec per loop

George
--


I always forget the 'del slice' method for clearing a list, thanks.

I think that returning a `chain` means that the function is not itself a 
generator. And so if the indata has length less than or equal
to the threshold (good_ones), an unhandled StopIteration is raised 
before the return statement is reached.



G.

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Re: Multiple values for one key

[Bruno Desthuilliers]

norseman a écrit :

Terry Reedy wrote:



Ron Brennan wrote:

Hello,
 
 
How would I create a dictionary that contains multiple values for one 
key.


Make the value a collection object (set or list if you plan to add and 
delete).



 I'd also like the key to be able to have duplicate entries.


Dict keys must be hashable and unique.

tjr

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First part I understand, second is still giving me a problem.

For some reason I still want keys to be dbf column headers.
like:

name:address:zip so forth
 --- --- --
guy: unknown:0
girl: 123 tiny street:12345
boy:321 here:3
gal:999 over there: 5
so forth

Thus one key has many values. And you can then index on whatever key(s) 
you wish - name,zip...


You can either use 1/ a list of dicts, or 2/ a dict mapping keys to lists.

1/
records = [
   {"name":"guy", "address":"unknown","zip":"0"},
   {"name":"girl", "address":"123 tiny street","zip":"12345"},
   {"name":"boy", "address":"321 here","zip":"3"},
   {"name":"gal", "address":"999 over there","zip":"5"},
]

keys = ("name", "address", "zip")

print ":".join(keys)
print "-" * len(":".join(keys))
for record in records:
data = [record[key] for key in keys]
print ":".join(data)


2/
records = dict(
name=["guy", "girl", "boy", "gal"],
address=["unknown","123 tiny street","321 there","999 over there"],
zip=["0", "12345", "3", "5"]
)

keys = ("name", "address", "zip")
nb_records = len(records[keys[0]])

print ":".join(keys)
print "-" * len(":".join(keys))
for i in xrange(nb_records):
data = [data[key][i] for key in keys]
print ":".join(data)


You are of course entitled the right to prefer the second solution, but 
then I hope I'll never have to maintain your code, since it's obviously 
not an appropriate data structure.



With billions plus records,


With billions plus records, it may be time to move to a serious RDBMS. 
Which btw will provide solution 1, or a lighter version of it using a 
list of tuples, ie:


cursor = connection.cursor()
cursor.execute("select name, address, zip from peoples")
records = cursor.fetchall()

# at this time, you have :
#records = [
#   ("guy", "unknown","0",),
#   ("girl", "123 tiny street","12345",),
#   ("boy", "321 here","3",),
#   ("gal", "999 over there", "5",),
#]


(snip)


OK - I know I missed the whole concept of a Python Dictionary.


Bad thing for you, since it's the central datastructure in Python.

I haven't 
read anything as yet that gives a clear picture of what it is and what 
it is for.


Then you failed to read the FineManual's tutorial, which is where you 
should have started:


http://docs.python.org/tut/node7.html#SECTION00750

Do yourself a favour : read the above first, then if you still have 
questions about dicts, we'll gladly try to help.


And do yourself another favour : learn about SQL, relational model and 
RDBMS.


(snip description of why the OP *really* wants a RDBMS)
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Re: def X(l=[]): weirdness. Python bug ?

[Andrew Lee]

Bart van Deenen wrote:

Hi all.

I've stumbled onto a python behavior that I don't understand at all.

Python 2.5.2 (r252:60911, Jul 31 2008, 17:28:52) 

# function 
def X(l=[]):

   l.append(1)
   print l

# first call of X
X()
[1]

#second call of X
X()
[1, 1]

Where does the list parameter 'l' live between the two successive calls of X(). 
Why is it not recreated with an empty list?

Is this correct behavior or is it a Python bug?
Does anyone have any pointers to the language documentation where this behavior 
is described?

Thanks all

Bart van Deenen



I happen to be reading about decorators at the moment:

from copy import deepcopy
def nodefault(myfunc):
myfunc_defaults = myfunc.func_defaults
def fresh(*args, **kwargs):
myfunc.func_defaults = deepcopy(myfunc_defaults)
return myfunc(*args, **kwargs)
return fresh

@nodefault
def X(l=[]):
l.append(1)
print l

>>> for i in range(1,6):
... X()
...
[1]
[1]
[1]
[1]
[1]


Which is just a very fancy way of doing:
def X(l=[]):
if l is None:
l = []
l.append(1)
print l

* sound of two pennies *
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Re: Wild Card String Comparison

[Cameron Laird]

In article <[EMAIL PROTECTED]>,
W. eWatson <[EMAIL PROTECTED]> wrote:
>Is it possible to do a search for a wild card string in another string. For 
>example, I'd like to find "v*.dat" in a string called bingo. v must be 
>matched against only the first character in bingo, and not simply found 
>somewhere in bingo, as might be the case for "*v*.dat".
.
.
.
Does this session leave any questions:

  python
  Python 2.4.4c0 (#2, Oct  2 2006, 00:57:46)
  [GCC 4.1.2 20060928 (prerelease) (Debian 4.1.1-15)] on linux2
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import re
  >>> pattern = "^v.*\.dat"
  >>> compiled = re.compile(pattern)
  >>> compiled.match("victory.dat")
  <_sre.SRE_Match object at 0xb7da2c60>
  >>> ms = compiled.match("victory.dat")
  >>> ms.group()
  "victory.dat"
  >>> compiled.match("avoid.dat")
  >>> # Notice the return value of "None".
  ...
  >>> import sys
  >>> sys.exit()

?
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Re: List of modules available for import inside Python?

[Fredrik Lundh]

[EMAIL PROTECTED] wrote:


Is there a way to view all the modules I have available for import
from within Python?
Like writing in the interpreter:
import.modules

Also, is there anything like Cpan for Python?


Isn't the most obvious answer to the first question this link?


depends on whether you want a list of the modules that you might be able 
to import, or the modules that are actually present on your system.




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Problem with list.insert

[SUBHABRATA]

Dear Group,
I wrote one program,
There is a dictionary.
There is an input string.
Every word of input string the word is matched against the dictionary
If the word of input string is matched against the dictionary it gives
the word of the dictionary.
But if it does not find it gives the original word.
After searching the words are joined back.
But as I am joining I am finding the words which are not available in
dictionary are printed in the last even if the word is given in the
first/middle.
Now, I want to take them in order.
I am applying a thumb rule that the position of the word of the string
is exact with the resultant string.
So, I am determining the word which is not in the dictionary, and its
position in the input string.
Now I am inserting it in the target string, for this I am splitting
both the given string and the output/result string.
Till now it is working fine.
But a problem happening is that if I insert it it is inserting same
words multiple times and the program seems to be an unending process.
What is the error happening?
If any one can suggest.
The code is given below:
import re
def wordchecker1(n):
# INPUTTING STRING
a1=raw_input("PRINT ONE ENGLISH SENTENCE FOR DICTIONARY CHECK:")
#CONVERTING TO LOWER CASE
a2=a1.lower()
#CONVERTING INTO LIST
a3=a2.split()
#DICTIONARY
a4=open("/python25/Changedict3.txt","r")
a5=a4.read()
a6=a5.split()
found=[]
not_found=[]
   #SEARCHING DICTIONARY
for x in a3:
a7="\n"
a8=a7+x
if a8 in a5:
a9=a5.index(a8)
a10=a5[a9:]
a11=re.search("\xe0.*?\n",a10)
a12=a11.group()
a13=a12[:-1]
found.append(a13)
elif a8 not in a5:
a14=x
not_found.append(a14)
else:
print "Error"
found.extend(not_found)
# THE OUTPUT
print "OUTPUT STRING IS"
a15=(' '.join(found))
#THE OUTPUT STRING
print a15
# SPLITTING OUTPUT STRING IN WORDS
a16=a15.split()
#TAKING OUT THE WORD FROM OUTPUT STRING
for word in a16:
#MATCHING WITH GIVEN STRING
a17=a2.find(word)
if a17>-1:
print "The word is found in the Source String"
a18=a3.index(word)
a19=a3[a18]
print a19
#INSERTING IN THE LIST OF TARGET STRING
a20=a16.insert(a18,a19)
print a16
a21=(" ".join(a16))
print a21
Best Regards,
Subhabrata.

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Re: cannot find object instance

[Bruno Desthuilliers]

jimgardener a écrit :

hi,
i am a python newbie..


From what I can see from your code, you're a newbie to programming in 
general...



while trying out some message passing between
two object instances i came across a problem


First point : you have both a circular dependency between ModuleA and 
ModuleB - which is better to avoid unless you really like headaches... 
You mention Java somewhere else, so I assume you have some at least some 
Java background. Point here is that Python is not Java, and doesn't 
restrict you to one ("public") class per module. IOW, if you have two 
strongly related classes (which is obviously the case here), better to 
put both in a same module.



moduleA.py

import moduleB
class MyClassA:
def __init__(self):
self.age=0
self.address=''
def createClassB(self):
self.objB=moduleB.MyClassB()


Why is this in a distinct method instead of being in the initializer ? 
And why is it named create*Class* when it creates an *instance* ?



def validate(self,age,address):
if(age >= 100 or address==''):
self.age=20;
self.address="Broadway,NewYork"
self.objB.display(self.age,self.address)
def callB(self):
self.objB.execute()


Looks like a somewhat messy, circonvoluted and arbitrary 
overcomplexificated control flow...



if __name__ == "__main__":
objA=MyClassA()
objA.createClassB()
objA.callB()

moduleB.py
--
import moduleA

class MyClassB:
def __init__(self):
self.createA()
def createA(self):
self.objA=moduleA.MyClassA()


You do understand that self.objA won't be the same MyClassA instance as 
the one that instanciated this instance of MyClassB, do you ?



def execute(self):
self.objA.validate(111,'')
def display(self,age,address):
print 'displaying:',str(age),address


You don't have to call str on age here.



when i run the code i get a message
AttributeError: MyClassA instance has no attribute 'objB'


Indeed.

You first create an instance of MyClassA named objA, call createClassB() 
on it which create an instance of MyClassB referenced by objA.objB.


When objA.objB is created, it itself creates another instance of 
MyClassA referenced by objA.objB.objA, which is totally distinct from 
objA...


Then you call objA.callB(),
which itself call objA.objB.execute(),
which in turn call objA.objB.objA.validate(),
which in turn call objA.objB.objA.objB.display().

But at this point, objA.objB.objA (which, I repeat, is *not* objA) has 
no attribute objB since you didn't call objA.objB.objA.createClassB()...


You could have understood this by yourself, either the way I did 
(mentally tracing program execution) or using a couple print statements 
in your code (to effectively trace program execution), or using the 
debugger...



Do i have to put a placeholder for objB in __init__ of MyClassA ?
is that why i get this error?someone please tell me how i can solve
this?  I tried to put self.objB=None but it didn't work..



Trying anything that comes to mind instead of trying to understand how 
things work is a well-known antipattern named "programming by accident". 
The best you can hope from this approach is that, for unknown reasons, 
things accidentally seem to work. Until the day where, for still unknown 
reasons, they either stop working, or it appears they never really 
worked at all.


Needless to say, this approach is a pure waste of time.


class ClassA(object):
def __init__(self, age=0, address=''):
self.age = age
self.address = address
self.b= ClassB(self)

def validate(self,age,address):
if(age >= 100 or address==''):
self.age=20;
self.address="Broadway,NewYork"
self.b.display(self.age, self.address)

def call_b(self):
self.b.execute()

class ClassB(object):
def __init__(self, a):
self.a = a
def execute(self):
self.a.validate(111,'')
def display(self, age, address):
print 'displaying: %s %s' % (age, address)

if __name__ == "__main__":
objA=ClassA()
objA.call_b()


Note that this is still uselessly messy and arbitrary 
overcomplificated... Such a ping-pong between two classes is more often 
than not a design smell.


HTH
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Re: Problem with list.insert

[Marc 'BlackJack' Rintsch]

On Thu, 28 Aug 2008 09:13:00 -0700, SUBHABRATA wrote:

> import re
> def wordchecker1(n):
> # INPUTTING STRING
> a1=raw_input("PRINT ONE ENGLISH SENTENCE FOR DICTIONARY CHECK:")
> #CONVERTING TO LOWER CASE
> a2=a1.lower()
> #CONVERTING INTO LIST
> a3=a2.split()
> #DICTIONARY
> a4=open("/python25/Changedict3.txt","r") a5=a4.read()
> a6=a5.split()
> found=[]
> not_found=[]
>#SEARCHING DICTIONARY
> for x in a3:
> a7="\n"
> a8=a7+x
> if a8 in a5:
> a9=a5.index(a8)
> a10=a5[a9:]
> a11=re.search("\xe0.*?\n",a10)
> a12=a11.group()
> a13=a12[:-1]
> found.append(a13)
> elif a8 not in a5:
> a14=x
> not_found.append(a14)
> else:
> print "Error"
> found.extend(not_found)
> # THE OUTPUT
> print "OUTPUT STRING IS"
> a15=(' '.join(found))
> #THE OUTPUT STRING
> print a15
> # SPLITTING OUTPUT STRING IN WORDS
> a16=a15.split()
> #TAKING OUT THE WORD FROM OUTPUT STRING for word in a16:
> #MATCHING WITH GIVEN STRING
> a17=a2.find(word)
> if a17>-1:
> print "The word is found in the Source String"
> a18=a3.index(word)
> a19=a3[a18]
> print a19
> #INSERTING IN THE LIST OF TARGET STRING
> a20=a16.insert(a18,a19)
> print a16
> a21=(" ".join(a16))
> print a21

a1, a2, a2, …, a20?  You must be kidding.  Please stop numbering names 
and use *meaningful* names instead!

Could you describe them problem better, with sample inputs and expected 
outputs.  There must be a better way that that unreadable mess above.

Ciao,
Marc 'BlackJack' Rintsch
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Re: cannot find object instance

[Marc 'BlackJack' Rintsch]

On Thu, 28 Aug 2008 08:35:07 -0700, jimgardener wrote:

> moduleA.py
> 
> import moduleB
>
> […]
> 
> moduleB.py
> --
> import moduleA
> 
> […]

Don't do that.  Circular imports are a code smell.  If two modules are 
coupled that tight it's usually a sign that you want just one module or 
factoring out something into a third module that is imported by both old 
modules.

Ciao,
Marc 'BlackJack' Rintsch
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Re: Multiple values for one key

[Tim Rowe]

2008/8/28 Bruno Desthuilliers <[EMAIL PROTECTED]>:

> You can either use 1/ a list of dicts, or 2/ a dict mapping keys to lists.
>
> 1/
> records = [
>   {"name":"guy", "address":"unknown","zip":"0"},
>   {"name":"girl", "address":"123 tiny street","zip":"12345"},
>   {"name":"boy", "address":"321 here","zip":"3"},
>   {"name":"gal", "address":"999 over there","zip":"5"},
> ]

I think I'd make a class with members name, address, zip, etc. Then
make a list of instances of that class or (better for access) identify
a primary key -- what *is* unique about each entry -- and use that as
a dictionary key with class instances as values. Or use a DBMS.
Certainly the original poster should read up on database design, or
chances are he'll have a nightmare maintaining referential integrity.

-- 
Tim Rowe
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Re: How to update value in dictionary?

[MRAB]

On Aug 27, 8:01 pm, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
> mblume wrote:
> >> 2) setdefault is your friend
>
> >> d = {}
> >> d['a'] = d.setdefault('a', 1) + 1
>
> > d['a'] = d.get('a', 1) + 1
>
> > seems to me a little better, as d['a'] doesn't get set twice, right?
>
> setdefault is pronounced "get, and set if necessary".  it only updates
> the dictionary if the key isn't already there:
>
>  >>> help({}.setdefault)
> Help on built-in function setdefault:
>
> setdefault(...)
>      D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D
>
> (since setdefault is a method, the second argument is evaluated whether
> it's used or not, but that's true for your approach as well, and isn't
> much of a problem for a light-weight object like the integer 1.)
>
Both

d['a'] = d.setdefault('a', 1) + 1

and

 d['a'] = d.get('a', 1) + 1

will set d['a'] to 2 if 'a' isn't initially in d.
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Re: Multiple values for one key

[Ron Brennan]

I have another question.

How would like to be able to add the contents on the values for one key.

key['20001']:[978, 345]

How can I do this?

Thanks,
Ron

On Thu, Aug 28, 2008 at 11:56 AM, Bruno Desthuilliers
<[EMAIL PROTECTED]> wrote:

> norseman a écrit :
>
>>  Terry Reedy wrote:
>>
>>>
>>>
>>> Ron Brennan wrote:
>>>
 Hello,
   How would I create a dictionary that contains multiple values for one
 key.

>>>
>>> Make the value a collection object (set or list if you plan to add and
>>> delete).
>>>
>>>  I'd also like the key to be able to have duplicate entries.

>>>
>>> Dict keys must be hashable and unique.
>>>
>>> tjr
>>>
>>> --
>>> http://mail.python.org/mailman/listinfo/python-list
>>>
>>> 
>> First part I understand, second is still giving me a problem.
>>
>> For some reason I still want keys to be dbf column headers.
>> like:
>>
>> name:address:zip so forth
>>  --- --- --
>> guy: unknown:0
>> girl: 123 tiny street:12345
>> boy:321 here:3
>> gal:999 over there: 5
>> so forth
>>
>> Thus one key has many values. And you can then index on whatever key(s)
>> you wish - name,zip...
>>
>
> You can either use 1/ a list of dicts, or 2/ a dict mapping keys to lists.
>
> 1/
> records = [
>   {"name":"guy", "address":"unknown","zip":"0"},
>   {"name":"girl", "address":"123 tiny street","zip":"12345"},
>   {"name":"boy", "address":"321 here","zip":"3"},
>   {"name":"gal", "address":"999 over there","zip":"5"},
> ]
>
> keys = ("name", "address", "zip")
>
> print ":".join(keys)
> print "-" * len(":".join(keys))
> for record in records:
>data = [record[key] for key in keys]
>print ":".join(data)
>
>
> 2/
> records = dict(
>name=["guy", "girl", "boy", "gal"],
>address=["unknown","123 tiny street","321 there","999 over there"],
>zip=["0", "12345", "3", "5"]
>)
>
> keys = ("name", "address", "zip")
> nb_records = len(records[keys[0]])
>
> print ":".join(keys)
> print "-" * len(":".join(keys))
> for i in xrange(nb_records):
>data = [data[key][i] for key in keys]
>print ":".join(data)
>
>
> You are of course entitled the right to prefer the second solution, but
> then I hope I'll never have to maintain your code, since it's obviously not
> an appropriate data structure.
>
> With billions plus records,
>>
>
> With billions plus records, it may be time to move to a serious RDBMS.
> Which btw will provide solution 1, or a lighter version of it using a list
> of tuples, ie:
>
> cursor = connection.cursor()
> cursor.execute("select name, address, zip from peoples")
> records = cursor.fetchall()
>
> # at this time, you have :
> #records = [
> #   ("guy", "unknown","0",),
> #   ("girl", "123 tiny street","12345",),
> #   ("boy", "321 here","3",),
> #   ("gal", "999 over there", "5",),
> #]
>
>
> (snip)
>
> OK - I know I missed the whole concept of a Python Dictionary.
>>
>
> Bad thing for you, since it's the central datastructure in Python.
>
> I haven't read anything as yet that gives a clear picture of what it is and
>> what it is for.
>>
>
> Then you failed to read the FineManual's tutorial, which is where you
> should have started:
>
> http://docs.python.org/tut/node7.html#SECTION00750
>
> Do yourself a favour : read the above first, then if you still have
> questions about dicts, we'll gladly try to help.
>
> And do yourself another favour : learn about SQL, relational model and
> RDBMS.
>
> (snip description of why the OP *really* wants a RDBMS)
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



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Re: cannot find object instance

[jimgardener]

On Aug 28, 9:35 pm, Bruno Desthuilliers  wrote:
Such a ping-pong between two classes is more often
> than not a design smell.


thanks Bruno,i understand my mistake..should have figured it out
myself
thanks again
jim

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Re: Problem with list.insert

[SUBHABRATA]

Some people in the room told I am kidding, but I learnt Python from
Python docs which gives examples like these,
But I write explicit comments,
an excerpt from python docs:
# Measure some strings:
... a = ['cat', 'window', 'defenestrate']
>>> for x in a:
... print x, len(x)
...
cat 3
window 6
defenestrate 12
But well, if you are suggesting improvement I'll surely listen.

The outputs are given in Hindi, it is a dictionary look up program,
the matching words are in Hindi, you may leave aside them.
How to debug the result string is to see the words which are in
English as the group page does not take italics so I am putting one
asterisk* after it
NO PROBLEM:
INPUT:
he has come
OUTPUT IS
उओह/ उन्होने रहेसाक्ता २.यात्राकरना
PROBLEM:
INPUT:
(i) Lincoln* has come
OUTPUT IS:
रहेसाक्ता २.यात्राकरना lincoln*
lincoln lincoln* रहेसाक्ता २.यात्राकरना lincoln
lincoln lincoln* lincoln* रहेसाक्ता २.यात्राकरना lincoln
….and increasing the number and seems a never ending process.
MY EXPEPECTED STRING IS:
lincoln रहेसाक्ता २.यात्राकरना lincoln^
The latter places marked^ I am editing don't worry for that,
though MY FINAL EXPECTED STRING IS:
lincoln रहेसाक्ता २.यात्राकरना
Best Regards,
Subhabrata.



Marc 'BlackJack' Rintsch wrote:
> On Thu, 28 Aug 2008 09:13:00 -0700, SUBHABRATA wrote:
>
> > import re
> > def wordchecker1(n):
> > # INPUTTING STRING
> > a1=raw_input("PRINT ONE ENGLISH SENTENCE FOR DICTIONARY CHECK:")
> > #CONVERTING TO LOWER CASE
> > a2=a1.lower()
> > #CONVERTING INTO LIST
> > a3=a2.split()
> > #DICTIONARY
> > a4=open("/python25/Changedict3.txt","r") a5=a4.read()
> > a6=a5.split()
> > found=[]
> > not_found=[]
> >#SEARCHING DICTIONARY
> > for x in a3:
> > a7="\n"
> > a8=a7+x
> > if a8 in a5:
> > a9=a5.index(a8)
> > a10=a5[a9:]
> > a11=re.search("\xe0.*?\n",a10)
> > a12=a11.group()
> > a13=a12[:-1]
> > found.append(a13)
> > elif a8 not in a5:
> > a14=x
> > not_found.append(a14)
> > else:
> > print "Error"
> > found.extend(not_found)
> > # THE OUTPUT
> > print "OUTPUT STRING IS"
> > a15=(' '.join(found))
> > #THE OUTPUT STRING
> > print a15
> > # SPLITTING OUTPUT STRING IN WORDS
> > a16=a15.split()
> > #TAKING OUT THE WORD FROM OUTPUT STRING for word in a16:
> > #MATCHING WITH GIVEN STRING
> > a17=a2.find(word)
> > if a17>-1:
> > print "The word is found in the Source String"
> > a18=a3.index(word)
> > a19=a3[a18]
> > print a19
> > #INSERTING IN THE LIST OF TARGET STRING
> > a20=a16.insert(a18,a19)
> > print a16
> > a21=(" ".join(a16))
> > print a21
>
> a1, a2, a2, …, a20?  You must be kidding.  Please stop numbering names
> and use *meaningful* names instead!
>
> Could you describe them problem better, with sample inputs and expected
> outputs.  There must be a better way that that unreadable mess above.
>
> Ciao,
>   Marc 'BlackJack' Rintsch
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Re: [Q] How to ignore the first line of the text read from a file

[norseman]

Benjamin Kaplan wrote:

On Thu, Aug 28, 2008 at 12:11 AM, [EMAIL PROTECTED] <
[EMAIL PROTECTED]> wrote:


Hello,

I am new to Python and have one simple question to which I cannot find
a satisfactory solution.
I want to read text line-by-line from a text file, but want to ignore
only the first line. I know how to do it in Java (Java has been my
primary language for the last couple of years) and following is what I
have in Python, but I don't like it and want to learn the better way
of doing it.

file = open(fileName, 'r')
lineNumber = 0
for line in file:
   if lineNumber == 0:
   lineNumber = lineNumber + 1
   else:
   lineNumber = lineNumber + 1
   print line

Can anyone show me the better of doing this kind of task?

Thanks in advance.

--



Files are iterators, and iterators can only go through the object once. Just
call next() before going in the for loop. Also, don't use "file" as a
variable name. It covers up the built-in type.

afile = open(file_name, 'r')
afile.next() #just reads the first line and doesn't do anything with it
for line in afile :
   print line



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==
actually:
import os

file = open(filename, 'r')
for line in file:
  dummy=line
  for line in file:
print line


is cleaner and faster.
If you need line numbers, pre-parse things, whatever, add where needed.

Steve
[EMAIL PROTECTED]
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epoch seconds from a datetime

[Richard Rossel]

Hi friends,
I need a little help here, I 'm stuck with epoch calculation issue.
I have this datetime:
date_new = datetime(*time.strptime('20080101T00','%Y%m%dT%H%M%S')
[0:6])
This date_new is in UTC
Now I need to know the seconds since epoch of this new date, so I run
this:
seconds = int(time.mktime(date_new.timetuple()))
but the seconds returned belongs to :
Tue, 01 Jan 2008 03:00:00 GMT
because the  localtime is in timezone 'America/Santiago': -3

I fix this trying to alter the TZ with time.tzset():
 os.environ['TZ'] = 'UTC'
time.tzset()

 and now I can gets the right epoch, but I can't restore the
previous TimeZone, I try with:
os.environ['TZ'] = '', but the time.tzset() doesn't back to the
original ( America/Santiago)

A solution should be set the os.environ['TZ']   to  'America/Santiago'
but I can't make a TZ hardcode because
the software should works on different timezones.

So the question, how can restore the system into original timezone, or
how to know the seconds since epoch
from UTC datetime without change the local system TIMEZONE.

please help

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Re: Problem with list.insert

[Diez B. Roggisch]

SUBHABRATA schrieb:

Some people in the room told I am kidding, but I learnt Python from
Python docs which gives examples like these,
But I write explicit comments,
an excerpt from python docs:
# Measure some strings:
... a = ['cat', 'window', 'defenestrate']

for x in a:

... print x, len(x)
...
cat 3
window 6
defenestrate 12
But well, if you are suggesting improvement I'll surely listen.


Please! Just because a tiny 3 lines example involing just *one* list 
doesn't give that a long & speaking name does not mean



The outputs are given in Hindi, it is a dictionary look up program,
the matching words are in Hindi, you may leave aside them.
How to debug the result string is to see the words which are in
English as the group page does not take italics so I am putting one
asterisk* after it
NO PROBLEM:
INPUT:
he has come
OUTPUT IS
उओह/ उन्होने रहेसाक्ता २.यात्राकरना
PROBLEM:
INPUT:
(i) Lincoln* has come
OUTPUT IS:
रहेसाक्ता २.यात्राकरना lincoln*
lincoln lincoln* रहेसाक्ता २.यात्राकरना lincoln
lincoln lincoln* lincoln* रहेसाक्ता २.यात्राकरना lincoln
….and increasing the number and seems a never ending process.
MY EXPEPECTED STRING IS:
lincoln रहेसाक्ता २.यात्राकरना lincoln^
The latter places marked^ I am editing don't worry for that,
though MY FINAL EXPECTED STRING IS:
lincoln रहेसाक्ता २.यात्राकरना
Best Regards,
Subhabrata.



Marc 'BlackJack' Rintsch wrote:

On Thu, 28 Aug 2008 09:13:00 -0700, SUBHABRATA wrote:


import re
def wordchecker1(n):
# INPUTTING STRING
a1=raw_input("PRINT ONE ENGLISH SENTENCE FOR DICTIONARY CHECK:")
#CONVERTING TO LOWER CASE
a2=a1.lower()
#CONVERTING INTO LIST
a3=a2.split()
#DICTIONARY
a4=open("/python25/Changedict3.txt","r") a5=a4.read()
a6=a5.split()
found=[]
not_found=[]
   #SEARCHING DICTIONARY
for x in a3:
a7="\n"
a8=a7+x
if a8 in a5:
a9=a5.index(a8)
a10=a5[a9:]
a11=re.search("\xe0.*?\n",a10)
a12=a11.group()
a13=a12[:-1]
found.append(a13)
elif a8 not in a5:
a14=x
not_found.append(a14)
else:
print "Error"
found.extend(not_found)
# THE OUTPUT
print "OUTPUT STRING IS"
a15=(' '.join(found))
#THE OUTPUT STRING
print a15
# SPLITTING OUTPUT STRING IN WORDS
a16=a15.split()
#TAKING OUT THE WORD FROM OUTPUT STRING for word in a16:
#MATCHING WITH GIVEN STRING
a17=a2.find(word)
if a17>-1:
print "The word is found in the Source String"
a18=a3.index(word)
a19=a3[a18]
print a19
#INSERTING IN THE LIST OF TARGET STRING
a20=a16.insert(a18,a19)
print a16
a21=(" ".join(a16))
print a21

a1, a2, a2, …, a20?  You must be kidding.  Please stop numbering names
and use *meaningful* names instead!

Could you describe them problem better, with sample inputs and expected
outputs.  There must be a better way that that unreadable mess above.

Ciao,
Marc 'BlackJack' Rintsch

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Re: Problem with list.insert

[Diez B. Roggisch]

Diez B. Roggisch schrieb:

SUBHABRATA schrieb:

Some people in the room told I am kidding, but I learnt Python from
Python docs which gives examples like these,
But I write explicit comments,
an excerpt from python docs:
# Measure some strings:
... a = ['cat', 'window', 'defenestrate']

for x in a:

... print x, len(x)
...
cat 3
window 6
defenestrate 12
But well, if you are suggesting improvement I'll surely listen.


Please! Just because a tiny 3 lines example involing just *one* list 
doesn't give that a long & speaking name does not mean


discard my last post - I accidentially pressed submit to early.

Numbering variable names surely is *not* found in any python example. 
Short names, as the examples are clear & don't require more meaningful 
names occur, yes. But nowhere you will find 2-figure enumerations.


Each book or tutorial about programming will teach you to use meaningful 
variables for your program.


As far as your explanation goes: there is *nothing* to be understood 
from a bunch of questionmarks + sometimes "lincoln" spread in between is 
not really helping.


This is most probably not your fault, as somehow the hindi get's twisted 
to the questionmarks - however, I suggest you provide an example where 
the hindi is replaced with english words (translations, or placeholders) 
- otherwise, you won't be understood, and can't be helped.


Diez
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Re: Python svn bindings for Subversion?

[Benjamin Kaplan]

On Thu, Aug 28, 2008 at 11:22 AM, Mike B <[EMAIL PROTECTED]> wrote:

> I'm trying to get Subversion 'hook scripts' working on an Ubuntu box and
> the
> following fails.
>
> from svn import fs, repos, core, delta
>
> As far as I can tell there are two Python Subversion libraries, 'pysvn' and
> 'svn':
> 'pysvn' from http://pysvn.tigris.org/ appears to be a client side
> interface and
> isn't what I need.
> 'svn' appears to be a SWIG wrapper and could be what I'm looking for, but I
> cannot find it anywhere.
>
> Can anyone point me in the right direction.
>
> Thanks
>
> Mike
>

I think the python-subversion package is the swig wrapper.
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Re: Problem with list.insert

[bearophileHUGS]

Subhabrata, it's very difficult for me to understand what your short
program has to do, or what you say. I think that formatting and code
style are important.

So I suggest you to give meaningful names to all your variable names,
to remove unused variables (like n), to add blank likes here and there
to separate logically separated parts of your program, or even better
to split it into functions. You can remove some intermediate function,
coalescing few logically related operations into a line, you can put
spaces around operators like = and after a commas, you can show an
usage example in English, so people can understand what the program is
supposed to to, you can avoid joining and then splitting strings
again, remove useless () around certain things.

This is a possible re-write of the first part of your code, it's not
exactly equal...


def input_words():
input_message = "Print one English sentence for dictionary check:
"
return raw_input(input_message).lower().split()


def load_dictionary():
return set(line.rstrip() for line in open("words.txt"))


def dictionary_search(dictionary, words):
found = []
not_found = []

for word in words:
if word in dictionary:
found.append(word)
else:
not_found.append(word)

return found + not_found


inwords = input_words()
dictionary = load_dictionary()
print dictionary_search(dictionary, inwords)


It's far from perfect, but you can use it as starting point for a
rewrite of your whole program.

Bye,
bearophile
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Re: List of modules available for import inside Python?

[Jason Scheirer]

On Aug 27, 11:04 pm, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
> ssecorp wrote:
> > Is there a way to view all the modules I have available for import
> > from within Python?
> > Like writing in the interpreter:
> > import.modules
>
> there's a helper script in the 2.5 source code kit that locates all
> existing standard modules:
>
> http://svn.python.org/projects/python/tags/r252/Doc/tools/listmodules.py
>
> to get all modules, remove the for-loop that follows after the comment
> "get rid of site packages".
>
> also see:
>
> http://effbot.org/zone/listmodules-cgi.htm
>
> 

I like to direct new users to pydoc's built-in HTTP server:

import pydoc
pydoc.gui()
(then click the 'open browser' button)
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Re: epoch seconds from a datetime

[Chris Rebert]

On Thu, Aug 28, 2008 at 10:18 AM, Richard Rossel <[EMAIL PROTECTED]> wrote:
> Hi friends,
> I need a little help here, I 'm stuck with epoch calculation issue.
> I have this datetime:
> date_new = datetime(*time.strptime('20080101T00','%Y%m%dT%H%M%S')
> [0:6])
> This date_new is in UTC
> Now I need to know the seconds since epoch of this new date, so I run
> this:
> seconds = int(time.mktime(date_new.timetuple()))
> but the seconds returned belongs to :
> Tue, 01 Jan 2008 03:00:00 GMT
> because the  localtime is in timezone 'America/Santiago': -3
>
> I fix this trying to alter the TZ with time.tzset():
>  os.environ['TZ'] = 'UTC'
> time.tzset()
>
>  and now I can gets the right epoch, but I can't restore the
> previous TimeZone, I try with:
> os.environ['TZ'] = '', but the time.tzset() doesn't back to the
> original ( America/Santiago)

I think you need to del os.environ['TZ'] rather than setting it to the
empty string.

On my box:
Python 2.5.1 (r251:54863, Feb  4 2008, 21:48:13)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
>>> import os, time
>>> time.asctime()
'Thu Aug 28 11:19:57 2008'
>>> #that's my correct local time
>>> time.tzname
('PST', 'PDT')
>>> #that's my correct timezone
>>> os.environ['TZ'] = 'UTC'
>>> time.tzset()
>>> time.tzname
('UTC', 'UTC')
>>> time.asctime()
'Thu Aug 28 18:20:33 2008'
>>> #we're clearly in UTC now
>>> del os.environ['TZ'] #this is the key line
>>> time.tzset()
>>> time.tzname
('PST', 'PDT')
>>> time.asctime()
'Thu Aug 28 11:21:05 2008'
>>> #and now we're back to my original timezone

Regards,
Chris

Follow the path of the Iguana...
Rebertia: http://rebertia.com
Blog: http://blog.rebertia.com

>
> A solution should be set the os.environ['TZ']   to  'America/Santiago'
> but I can't make a TZ hardcode because
> the software should works on different timezones.
>
> So the question, how can restore the system into original timezone, or
> how to know the seconds since epoch
> from UTC datetime without change the local system TIMEZONE.
>
> please help
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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Re: no string.downer() ?

[Tobiah]

> Never ascribe to humour that which can be adequately explained by
> increadible stupidity!  

I love the irony.  Don't feel bad.  I recently corrected
someone's 'grammer' with a similar tone.
** Posted from http://www.teranews.com **
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Re: Identifying the start of good data in a list

[castironpi]

On Aug 27, 3:42 pm, George Sakkis <[EMAIL PROTECTED]> wrote:
> Below are two more versions that pass all the doctests: the first
> works only for lists and modifies them in place and the second works
> for arbitrary iterables:
>
> def clean_inplace(seq, good_ones=4):
>     start = 0
>     n = len(seq)
>     while start < n:
>         try: end = seq.index(0, start)
>         except ValueError: end = n
>         if end-start >= good_ones:
>             break
>         start = end+1
>     del seq[:start]
>
> def clean_iter(iterable, good_ones=4):
>     from itertools import chain, islice, takewhile, dropwhile
>     iterator = iter(iterable)
>     is_zero = float(0).__eq__
>     while True:
>         # consume all zeros up to the next non-zero
>         iterator = dropwhile(is_zero, iterator)
>         # take up to `good_ones` non-zeros
>         good = list(islice(takewhile(bool,iterator), good_ones))
>         if not good: # iterator exhausted
>             return iterator
>         if len(good) == good_ones:
>             # found `good_ones` consecutive non-zeros;
>             # chain them to the rest items and return them
>             return chain(good, iterator)
>
> HTH,
> George

You gave me an idea-- maybe an arbitrary 'lookahead' iterable could be
useful.  I haven't seen them that much on the newsgroup, but more than
once.  IOW a buffered consumer.  Something that you could check a
fixed number of next elements of.  You might implement it as a
iterator with a __getitem__ method.

Example, unproduced:

>>> import itertools
>>> a= itertools.count( )
>>> a.next()
0
>>> a.next()
1
>>> a[ 3 ]
5
>>> a.next()
2
>>> a[ 3 ]
6

Does this make sense at all?
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Re: epoch seconds from a datetime

[Richard Rossel]

On 28 ago, 14:25, "Chris Rebert" <[EMAIL PROTECTED]> wrote:
> On Thu, Aug 28, 2008 at 10:18 AM, Richard Rossel <[EMAIL PROTECTED]> wrote:
> > Hi friends,
> > I need a little help here, I 'm stuck with epoch calculation issue.
> > I have this datetime:
> > date_new = datetime(*time.strptime('20080101T00','%Y%m%dT%H%M%S')
> > [0:6])
> > This date_new is in UTC
> > Now I need to know the seconds since epoch of this new date, so I run
> > this:
> > seconds = int(time.mktime(date_new.timetuple()))
> > but the seconds returned belongs to :
> > Tue, 01 Jan 2008 03:00:00 GMT
> > because the  localtime is in timezone 'America/Santiago': -3
>
> > I fix this trying to alter the TZ with time.tzset():
> >  os.environ['TZ'] = 'UTC'
> > time.tzset()
>
> >  and now I can gets the right epoch, but I can't restore the
> > previous TimeZone, I try with:
> > os.environ['TZ'] = '', but the time.tzset() doesn't back to the
> > original ( America/Santiago)
>
> I think you need to del os.environ['TZ'] rather than setting it to the
> empty string.
>
> On my box:
> Python 2.5.1 (r251:54863, Feb  4 2008, 21:48:13)
> [GCC 4.0.1 (Apple Inc. build 5465)] on darwin>>> import os, time
> >>> time.asctime()
>
> 'Thu Aug 28 11:19:57 2008'>>> #that's my correct local time
> >>> time.tzname
> ('PST', 'PDT')
> >>> #that's my correct timezone
> >>> os.environ['TZ'] = 'UTC'
> >>> time.tzset()
> >>> time.tzname
> ('UTC', 'UTC')
> >>> time.asctime()
>
> 'Thu Aug 28 18:20:33 2008'>>> #we're clearly in UTC now
> >>> del os.environ['TZ'] #this is the key line
> >>> time.tzset()
> >>> time.tzname
> ('PST', 'PDT')
> >>> time.asctime()
>
> 'Thu Aug 28 11:21:05 2008'
>
> >>> #and now we're back to my original timezone


Thanks Chris, and also I found that with reload(time)  works too

--
Richard Rossel
Ing. Civil Informatico
Valparaiso, Chile
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Re: no string.downer() ?

[Fredrik Lundh]

Tobiah wrote:


Never ascribe to humour that which can be adequately explained by
increadible stupidity!  


I love the irony.


Muphry's law.



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Re: Python multimap

[brad]

Carl Banks wrote:

Out of curiosity, what does a true multimap solve that a dictionary of
lists not solve?


Nothing really. I went with a variation of the suggested work around... 
it's just that with Python I don't normally have to use work arounds and 
 normally one obvious approach is correct:




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Re: Multiple values for one key

[Chris Rebert]

On Thu, Aug 28, 2008 at 10:02 AM, Ron Brennan <[EMAIL PROTECTED]> wrote:
> I have another question.
>
> How would like to be able to add the contents on the values for one key.
>
> key['20001']:[978, 345]

I'm assuming that by this you meant:
assert the_dict['20001'] == [978, 345]

>
> How can I do this?

sum(the_dict['20001']) #=> 1323

Regards,
Chris

Follow the path of the Iguana...
Rebertia: http://rebertia.com
Blog: http://blog.rebertia.com

>
> Thanks,
> Ron
>
> On Thu, Aug 28, 2008 at 11:56 AM, Bruno Desthuilliers
> <[EMAIL PROTECTED]> wrote:
>>
>> norseman a écrit :
>>>
>>> Terry Reedy wrote:


 Ron Brennan wrote:
>
> Hello,
>   How would I create a dictionary that contains multiple values for one
> key.

 Make the value a collection object (set or list if you plan to add and
 delete).

>  I'd also like the key to be able to have duplicate entries.

 Dict keys must be hashable and unique.

 tjr

 --
 http://mail.python.org/mailman/listinfo/python-list

>>> 
>>> First part I understand, second is still giving me a problem.
>>>
>>> For some reason I still want keys to be dbf column headers.
>>> like:
>>>
>>> name:address:zip so forth
>>>  --- --- --
>>> guy: unknown:0
>>> girl: 123 tiny street:12345
>>> boy:321 here:3
>>> gal:999 over there: 5
>>> so forth
>>>
>>> Thus one key has many values. And you can then index on whatever key(s)
>>> you wish - name,zip...
>>
>> You can either use 1/ a list of dicts, or 2/ a dict mapping keys to lists.
>>
>> 1/
>> records = [
>>   {"name":"guy", "address":"unknown","zip":"0"},
>>   {"name":"girl", "address":"123 tiny street","zip":"12345"},
>>   {"name":"boy", "address":"321 here","zip":"3"},
>>   {"name":"gal", "address":"999 over there","zip":"5"},
>> ]
>>
>> keys = ("name", "address", "zip")
>>
>> print ":".join(keys)
>> print "-" * len(":".join(keys))
>> for record in records:
>>data = [record[key] for key in keys]
>>print ":".join(data)
>>
>>
>> 2/
>> records = dict(
>>name=["guy", "girl", "boy", "gal"],
>>address=["unknown","123 tiny street","321 there","999 over there"],
>>zip=["0", "12345", "3", "5"]
>>)
>>
>> keys = ("name", "address", "zip")
>> nb_records = len(records[keys[0]])
>>
>> print ":".join(keys)
>> print "-" * len(":".join(keys))
>> for i in xrange(nb_records):
>>data = [data[key][i] for key in keys]
>>print ":".join(data)
>>
>>
>> You are of course entitled the right to prefer the second solution, but
>> then I hope I'll never have to maintain your code, since it's obviously not
>> an appropriate data structure.
>>
>>> With billions plus records,
>>
>> With billions plus records, it may be time to move to a serious RDBMS.
>> Which btw will provide solution 1, or a lighter version of it using a list
>> of tuples, ie:
>>
>> cursor = connection.cursor()
>> cursor.execute("select name, address, zip from peoples")
>> records = cursor.fetchall()
>>
>> # at this time, you have :
>> #records = [
>> #   ("guy", "unknown","0",),
>> #   ("girl", "123 tiny street","12345",),
>> #   ("boy", "321 here","3",),
>> #   ("gal", "999 over there", "5",),
>> #]
>>
>>
>> (snip)
>>
>>> OK - I know I missed the whole concept of a Python Dictionary.
>>
>> Bad thing for you, since it's the central datastructure in Python.
>>
>>> I haven't read anything as yet that gives a clear picture of what it is
>>> and what it is for.
>>
>> Then you failed to read the FineManual's tutorial, which is where you
>> should have started:
>>
>> http://docs.python.org/tut/node7.html#SECTION00750
>>
>> Do yourself a favour : read the above first, then if you still have
>> questions about dicts, we'll gladly try to help.
>>
>> And do yourself another favour : learn about SQL, relational model and
>> RDBMS.
>>
>> (snip description of why the OP *really* wants a RDBMS)
>> --
>> http://mail.python.org/mailman/listinfo/python-list
>
>
>
> --
> FYI, my email address is changing. My rogers account will be deactivated
> shortly.  From now on please use:
> [EMAIL PROTECTED]
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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Re: struct.Struct random access

[castironpi]

On Aug 28, 1:59 am, Tim Roberts <[EMAIL PROTECTED]> wrote:
> castironpi <[EMAIL PROTECTED]> wrote:
>
> >I'd like to seriously nominate this idea and get a considered opinion
> >on it.
>
> >struct.Struct lets you encode Python objects into structured memory.
> >It accepts a format string, and optionally a buffer and offset to/from
> >which to read/write the structure.  What do you think of random access
> >to the results?  To avoid Marc's concern about meaningless anonymous
> >record entries, model the constructor after 'namedtuple' type.
>
> >(unproduced)
>  packer= struct.Struct( 'IIIf255p', 'i1 i2 i3 afloat name' )
>  packer.pack_into( buf, off, 10, 20, 30, 0.5, 'abc' )
>  packer.unpack_from( buf, off, 'i3' )
> >30
>  packer.unpack_from( buf, off )
> >( 10, 20, 30, 0.5, 'abc' )
>  packer.pack_into( buf, off, 'i1', 12 )
>
> What data type would you expect "buf" to be?  Your design requires it to be
> both an input and an output parameter.  Today's "struct" converts into and
> out of a string, and strings are immutable.  So, to continue with that
> standard, you would have to pass a string into "pack_into" and have the
> modified result returned as an output:
>
>     buf = packer.pack_into( None, 0, 10, 20, 30, 0.5, 'abc' )
>     buf = packer.pack_into( buf, 0, 'i1', 12 )
>
> In the end, I'm not sure you are really saving anything.
>
> >Even in sequential access speed benefits, by avoiding the construction
> >of n-1 objects.
>
> This is a fairly major change, because it requires a "struct.Struct" object
> to maintain state, something that the "struct" module currently does not
> do.
>
> In my personal opinion, this is a rather large and confusing change, for
> very little benefit.
> --
> Tim Roberts, [EMAIL PROTECTED]
> Providenza & Boekelheide, Inc.

CMIIW correct me if I'm wrong, I don't think that pack_into returns a
value the way that pack does.

The syntax is ambiguous in the case of two-element structs: are you
packing a new struct or assigning a field?  Maybe the field name needs
a keyword.  A field name can be a third argument in unpack_from
regardless, however.  Or use the field name as keyword:
strt.pack_into( buf, off, i1= 32 ).

I just tried an experiment with an Mmap and PyObject_AsWriteBuffer.
Mmaps could work but you would not be able to use arbitrary strings.
You would have to specially allocate a ctypes buffer with a size to
match the packed size of the structure.
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Re: Pythoncom and pywintypes

[Vistro]

A Reinstall seems to have done nothing...

On Thu, Aug 28, 2008 at 4:49 AM, Gabriel Genellina
<[EMAIL PROTECTED]>wrote:

> En Wed, 27 Aug 2008 21:17:22 -0300, Vistro <[EMAIL PROTECTED]> escribi�:
>
>  Hey, there. I've been coding in python for about three weeks now. I have
>> made basic games, tools to check forum PMs for me, and other general
>> utilities with python, but I'm now encountering problems.
>>
>> http://ubuntuforums.org/archive/index.php/t-511211.html
>>
>> I want to do that, and I have installed both sets needed from source
>> forge,
>> but I always get this issue when I run the code, and there isn't a single
>> listing on the internet that addresses this.
>>
>> 
>>
>> Traceback (most recent call last):
>>  File "C:/Documents and Settings/Guest Editor/Desktop/key.py", line 3, in
>> 
>>import pythoncom
>>  File "C:\Python25\lib\site-packages\pythoncom.py", line 2, in 
>>import pywintypes
>> ImportError: No module named pywintypes
>>
>> I've installed pythoncom right from the box. I don't know whats wrong, but
>> I'm sure it has something to do with my stupidity.
>>
>
> Reinstalling the pywin32 package should fix that, I presume.
>
>  BUT, here is the strangest part.
>>
>> # Magic utility that "redirects" to pythoncomxx.dll
>> import pywintypes
>> pywintypes.__import_pywin32_system_module__("pythoncom", globals())
>>
>>
>> That is ALL that pythoncom.py seems to be. ALL that.
>>
>> I think that it's trying to import something, THEN tell the interpreter
>> where it is. That seems kinda stupid.
>>
>
> In fact that __import_whatever function does a rather complex task, it must
> ensure that the *right* pywintypes25.dll (or pythoncom25.dll) is loaded,
> even when it's implicitely loaded.
>
> --
> Gabriel Genellina
>
> --
> http://mail.python.org/mailman/listinfo/python-list
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Re: Problem with list.insert

[castironpi]

On Aug 28, 11:13 am, SUBHABRATA <[EMAIL PROTECTED]> wrote:
> Dear Group,
> I wrote one program,
> There is a dictionary.
> There is an input string.
> Every word of input string the word is matched against the dictionary
> If the word of input string is matched against the dictionary it gives
> the word of the dictionary.
> But if it does not find it gives the original word.
> After searching the words are joined back.
> But as I am joining I am finding the words which are not available in
> dictionary are printed in the last even if the word is given in the
> first/middle.
> Now, I want to take them in order.
> I am applying a thumb rule that the position of the word of the string
> is exact with the resultant string.
> So, I am determining the word which is not in the dictionary, and its
> position in the input string.
> Now I am inserting it in the target string, for this I am splitting
> both the given string and the output/result string.
> Till now it is working fine.
> But a problem happening is that if I insert it it is inserting same
> words multiple times and the program seems to be an unending process.
> What is the error happening?
> If any one can suggest.
> The code is given below:

Warning, -spoiler-.

Instead split up your inputs first thing.

trans= { 'a': 'A', 'at': 'AT', 'to': 'TO' }
sample= 'a boy at the park walked to the tree'
expected= 'A boy AT the park walked TO the tree'

sample_list= sample.split( )
for i, x in enumerate( sample_list ):
if x in trans:
sample_list[ i ]= trans[ x ]

result= ' '.join( sample_list )
print result
assert result== expected

Then replace them as you visit each one, and join them later.
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Sending e-mail

[peter . jones . rpi]

I work at a training center and I would like to use Python to generate
a number of certificates and then e-mail them. The certificates are a
problem for another day - right now I just want to figure out how to
send an e-mail.

I confess I don't know much about the protocol(s) for e-mail. In PHP
using CodeIgniter, the same task was amazingly easy. I think this is a
bit harder because I'm not executing code on a remote machine that has
its own SMTP server. According to (http://www.devshed.com/c/a/Python/
Python-Email-Libraries-SMTP-and-Email-Parsing/), I need to use the
SMTP object found in the smtplib module to initiate a connection to a
server before I can send. I want to use Gmail, but on the following
input it stalls and then raises smtplib.SMTPServerDisconnected:

server = SMTP("smtp.gmail.com")

I also pinged smtp.gmail.com and tried it with the dotted quad IP as a
string. Am I on the right track? Is this a problem with gmail, or have
I gotten an assumption wrong?

Here's a thought: Could I use SMTPServer (http://docs.python.org/lib/
node620.html) to obviate the need to have anything to do with Gmail?
What would be the limitations on that? Could I successfully do this
and wrap the whole thing up in a black box? What modules would I need?

Thanks.
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Re: Sending e-mail

[Waldemar Osuch]

On Aug 28, 12:52 pm, [EMAIL PROTECTED] wrote:
> I work at a training center and I would like to use Python to generate
> a number of certificates and then e-mail them. The certificates are a
> problem for another day - right now I just want to figure out how to
> send an e-mail.
>
> I confess I don't know much about the protocol(s) for e-mail. In PHP
> using CodeIgniter, the same task was amazingly easy. I think this is a
> bit harder because I'm not executing code on a remote machine that has
> its own SMTP server. According to (http://www.devshed.com/c/a/Python/
> Python-Email-Libraries-SMTP-and-Email-Parsing/), I need to use the
> SMTP object found in the smtplib module to initiate a connection to a
> server before I can send. I want to use Gmail, but on the following
> input it stalls and then raises smtplib.SMTPServerDisconnected:
>
> server = SMTP("smtp.gmail.com")
>
> I also pinged smtp.gmail.com and tried it with the dotted quad IP as a
> string. Am I on the right track? Is this a problem with gmail, or have
> I gotten an assumption wrong?
>
> Here's a thought: Could I use SMTPServer (http://docs.python.org/lib/
> node620.html) to obviate the need to have anything to do with Gmail?
> What would be the limitations on that? Could I successfully do this
> and wrap the whole thing up in a black box? What modules would I need?
>
> Thanks.

Gmail SMTP server needs authentication.
I little googling found this example.
I did not test it if it works but it could be starting point.

http://codecomments.wordpress.com/2008/01/04/python-gmail-smtp-example/
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Re: Sending e-mail

[Vistro]

I used that code before, and it did not do what it needed to do. If you are
just sending text, this usually works for me.

def sendMail():

## Parameters for SMTP session
port=587
SMTPserver=  'smtp.gmail.com'
SMTPuser= 'gmail username, which is your gmail address'
pw= 'your gmail password'
SENDER= SMTPuser


## Message details
FROM=  SENDER
TO= 'whoever you want to send it to'
CC=FROM
##RECEIVERS= (TO, CC)  ##proper way to send to both TO and CC
RECEIVERS= (TO,)  ## ignore the CC address


subject= 'subject here'
message= 'message here'


print 'Please wait...'
(SMTPserver,SMTPuser)
session = smtplib.SMTP(SMTPserver,port)
session.set_debuglevel(0)  # set debug level to 1 to see details
session.ehlo(SMTPuser)  # say hello
session.starttls()  # TLS needed
session.ehlo(SMTPuser)  # say hello again, not sure why
session.login(SMTPuser, pw)


##Create HEADER + MESSAGE
HEADER= 'From: %s\r\n' % FROM
HEADER= HEADER + 'To: %s\r\n' % TO
HEADER= HEADER + 'Cc: %s\r\n' % CC
HEADER= HEADER + 'Subject: %s\r\n' % subject
BODY= HEADER + '\r\n' + message



SMTPresult = session.sendmail(SENDER, RECEIVERS, BODY)  ## send email


session.close()

On Thu, Aug 28, 2008 at 1:52 PM, <[EMAIL PROTECTED]> wrote:

> I work at a training center and I would like to use Python to generate
> a number of certificates and then e-mail them. The certificates are a
> problem for another day - right now I just want to figure out how to
> send an e-mail.
>
> I confess I don't know much about the protocol(s) for e-mail. In PHP
> using CodeIgniter, the same task was amazingly easy. I think this is a
> bit harder because I'm not executing code on a remote machine that has
> its own SMTP server. According to (http://www.devshed.com/c/a/Python/
> Python-Email-Libraries-SMTP-and-Email-Parsing/),
> I need to use the
> SMTP object found in the smtplib module to initiate a connection to a
> server before I can send. I want to use Gmail, but on the following
> input it stalls and then raises smtplib.SMTPServerDisconnected:
>
> server = SMTP("smtp.gmail.com")
>
> I also pinged smtp.gmail.com and tried it with the dotted quad IP as a
> string. Am I on the right track? Is this a problem with gmail, or have
> I gotten an assumption wrong?
>
> Here's a thought: Could I use SMTPServer (http://docs.python.org/lib/
> node620.html ) to obviate the
> need to have anything to do with Gmail?
> What would be the limitations on that? Could I successfully do this
> and wrap the whole thing up in a black box? What modules would I need?
>
> Thanks.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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ImageTk.Photoimage not displayed

[harryos]

hi
i am trying to display an image on a canvas in a gui made with Tkinter
widgets


class PhotoDisplay:
def __init__(self,parent):
self.mainframe = Frame(parent,background="grey")
.
#added a subframe to hold canvas and button

   self.canvFrame=Frame(self.mainframe,...)
   
   self.mycanvas=Canvas(self.canvFrame,...)
   ...

def okbuttonClick(self):
self.mycanvas.delete(ALL)
myimagename=...#get an imagefilename from somewhere..
self.showSelectedImage(myimagename)

def showSelectedImage(self,imageName):
myimg=ImageTk.PhotoImage(file=imageName)
imgtag=self.mycanvas.create_image(70,100,image=myimg)
self.mycanvas.update_idletasks()


when i click the button ,the image is displayed for a fraction of a
second on the canvas and disappears.I couldn't figure out why this is
happening.I am quite new to Tkinter and still going  thru Fredrik
Lundh's intro to tkinter..can someone tell me if i am doing sthing
wrong here?
thanks in advance
harry
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file data to list

[Anish Chapagain]

Hi!!
I am facing problem for extracting file data to the list so as to have
graph plotted through list.
my file(eg: data.txt) is having data like this,

cnt0001a 29000 xretya 01
cnt0002a 29850 brishal 02
cnt0003a 31250 kristal 03

from here, I need to copy data 29000, 29850, 31250 into a single list
and
01, 02, 03 to another so as to plot graph using these value.

regard's
NepaliWorld
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Re: ImageTk.Photoimage not displayed

[Guilherme Polo]

On Thu, Aug 28, 2008 at 4:07 PM, harryos <[EMAIL PROTECTED]> wrote:
> hi
> i am trying to display an image on a canvas in a gui made with Tkinter
> widgets
>
>
> class PhotoDisplay:
>def __init__(self,parent):
>self.mainframe = Frame(parent,background="grey")
>.
>#added a subframe to hold canvas and button
>
>   self.canvFrame=Frame(self.mainframe,...)
>   
>   self.mycanvas=Canvas(self.canvFrame,...)
>   ...
>
>def okbuttonClick(self):
>self.mycanvas.delete(ALL)
>myimagename=...#get an imagefilename from somewhere..
>self.showSelectedImage(myimagename)
>
>def showSelectedImage(self,imageName):
>myimg=ImageTk.PhotoImage(file=imageName)
>imgtag=self.mycanvas.create_image(70,100,image=myimg)
>self.mycanvas.update_idletasks()
>
>
> when i click the button ,the image is displayed for a fraction of a
> second on the canvas and disappears.I couldn't figure out why this is
> happening.I am quite new to Tkinter and still going  thru Fredrik
> Lundh's intro to tkinter..can someone tell me if i am doing sthing
> wrong here?

You have to keep a reference to these images you are creating,
otherwise as soon as those methods finishes they are gone.

> thanks in advance
> harry
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
-- Guilherme H. Polo Goncalves
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Re: file data to list

[bearophileHUGS]

Anish Chapagain:
> cnt0001a 29000 xretya 01
> cnt0002a 29850 brishal 02
> cnt0003a 31250 kristal 03
> from here, I need to copy data 29000, 29850, 31250 into a single list
> and
> 01, 02, 03 to another so as to plot graph using these value.

This may offer you a starting point:

>>> line = "cnt0003a 31250 kristal 03"
>>> parts = line.split()
>>> parts
['cnt0003a', '31250', 'kristal', '03']
>>> parts[1], parts[3]
('31250', '03')
>>> map(int, [parts[1], parts[3]])
[31250, 3]

Bye,
bearophile
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re.compile versus r''

[Terrence Brannon]

Hello, I'm using a tool (PLY) which apparently expects the tokens to
be created using r''

But because one token is a rather complex regular expression, I want
to create the regular expression programmatically.

How can I generate a string and then create something of the same type
that the r'' function does?

Concretely, in the program below, consonant is not the same type as
t_NAME, but I assume that it needs to be for PLY to use it for
tokenizing:

import re

t_NAME   = r'[a-zA-Z_][a-zA-Z0-9_]*'

guttural   = 'kh?|gh?|\"n'
palatal= '(?:chh?|jh?|\~n)'
cerebral   = '\.(?:th?|dh?|n)'
dental = '(?:th?|dh?|n)'
semivowel  = '[yrlv]'
sibilant   = '[\"\.]?s'
aspirant   = 'h'

consonant = re.compile('|'.join([guttural , palatal , cerebral ,
dental , semivowel , sibilant , aspirant]))

print consonant
print t_NAME
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Re: Sending e-mail

[gordyt]

Peter here is an example.  I just tried it and it works fine.

from smtplib import SMTP
HOST = "smtp.gmail.com"
PORT = 587
ACCOUNT = ""  # put your gmail email account name here
PASSWORD = ""  # put your gmail email account password here

def send_email(to_addrs, subject, msg):
server = SMTP(HOST,PORT)
server.set_debuglevel(1)# you don't need this
server.ehlo()
server.starttls()
server.ehlo()
server.login(ACCOUNT, PASSWORD)
server.sendmail(ACCOUNT, to_addrs,
"""From: %s\r\nTo: %s\r\nSubject: %s\r\n\r\n%s\r\n.\r\n""" % (
ACCOUNT, ",".join(to_addrs), subject, msg
)
)
server.quit()

if __name__ == "__main__":
send_email( ['[EMAIL PROTECTED]'], 'this is just a test',
"hello world!" )
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[MacOS X] plat-mac/errors.rsrc.df.rsrc not installed/created

[Christian Ebert]

Hi,

I am on MacOS 10.4.11, and have a minor recurring problem, when
using my own Python installation.

I only stumbled over it when using http operations with the
Mercurial SCM, and my /tmp/ folder was clobbered with *.rsrc
temporary files.

Some references:
http://www.selenic.com/pipermail/mercurial/2007-October/015039.html
and, as I forgot about it :( :
http://www.selenic.com/pipermail/mercurial/2008-August/021072.html

Apparently for some stuff plat-mac/macresource.py needs to create
plat-mac/errors.rsrc.df.rsrc. If that fails, at least that is how
I read macresource.py, it creates them via mkstemp in /tmp/.

Once I recognize the problem I can work around it by either

$ sudo mv /tmp/tmp.rsrc 
/usr/local/lib/python2.5/plat-mac/errors.rsrc.df.rsrc

or by temporarily "chown myname plat-mac", and, once the file is
created, "chown root plat-mac" again.

My 2.5.2 install is under /usr/local, but other Mac users with
the same setup, do not have the problem.

I don't need/want the Apple Framework install, and again, others
do not have the problem with this setup.

Anyone any ideas?

The best I could google was
http://bugs.python.org/issue763708
but this seems encoding related.

TIA

c
-- 
  Was heißt hier Dogma, ich bin Underdogma!
[ What the hell do you mean dogma, I am underdogma. ]

_F R E E_  _V I D E O S_  -->>  http://www.blacktrash.org/underdogma/
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Re: file data to list

[Marc 'BlackJack' Rintsch]

On Thu, 28 Aug 2008 12:11:39 -0700, Anish Chapagain wrote:

> I am facing problem for extracting file data to the list so as to have
> graph plotted through list.
> my file(eg: data.txt) is having data like this,
> 
> cnt0001a 29000 xretya 01
> cnt0002a 29850 brishal 02
> cnt0003a 31250 kristal 03
> 
> from here, I need to copy data 29000, 29850, 31250 into a single list
> and 01, 02, 03 to another so as to plot graph using these value.

Then work through the tutorial in the documentation, pay attention to 
strings, lists, files, and their methods.  The try to implement it and 
come back with some source code and specific questions.

Ciao,
Marc 'BlackJack' Rintsch
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Re: re.compile versus r''

[Terrence Brannon]

Oh my god, how embarrassing. the r'' notation is to create raw string


I thought it was some form of blessing a string into a regular
expression class.

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Re: Python multimap

[Carl Banks]

On Aug 28, 2:41 pm, brad <[EMAIL PROTECTED]> wrote:
> Carl Banks wrote:
> > Out of curiosity, what does a true multimap solve that a dictionary of
> > lists not solve?
>
> Nothing really. I went with a variation of the suggested work around...
> it's just that with Python I don't normally have to use work arounds and
>   normally one obvious approach is correct:

Might I suggest that the C++ multimap is the workaround, rather than
the Python way of using dicts or lists or dicts of sets?

It was too much programming overhead and line noise confusion to
define nested templates to hold your nested data structures in C++, so
the STL provided a container that eliminated the nesting.  In Python,
the obvious nested way to do it is easy, especially now with
defaultdicts, so there was no reason to provide a multimap.


Carl Banks
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Re: re.compile versus r''

[Fredrik Lundh]

Terrence Brannon wrote:


Hello, I'm using a tool (PLY) which apparently expects the tokens to
be created using r''

But because one token is a rather complex regular expression, I want
to create the regular expression programmatically.

How can I generate a string and then create something of the same type
that the r'' function does?


r'' is an alternative syntax for string literals that affects how escape 
sequences are interpreted; there's no separate string type for strings 
created by this syntax.




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Re: re.compile versus r''

[Chris Rebert]

On Thu, Aug 28, 2008 at 12:23 PM, Terrence Brannon <[EMAIL PROTECTED]> wrote:
> Hello, I'm using a tool (PLY) which apparently expects the tokens to
> be created using r''
>
> But because one token is a rather complex regular expression, I want
> to create the regular expression programmatically.
>
> How can I generate a string and then create something of the same type
> that the r'' function does?

The "r" prefix isn't a function or a type, it's merely a special
literal syntax for strings that's handy when you're writing regexes
and therefore have to deal with another level of backslash escaping.
See the second to last paragraph of
http://docs.python.org/ref/strings.html  for more info.

Regards,
Chris

>
> Concretely, in the program below, consonant is not the same type as
> t_NAME, but I assume that it needs to be for PLY to use it for
> tokenizing:
>
> import re
>
> t_NAME   = r'[a-zA-Z_][a-zA-Z0-9_]*'
>
> guttural   = 'kh?|gh?|\"n'
> palatal= '(?:chh?|jh?|\~n)'
> cerebral   = '\.(?:th?|dh?|n)'
> dental = '(?:th?|dh?|n)'
> semivowel  = '[yrlv]'
> sibilant   = '[\"\.]?s'
> aspirant   = 'h'
>
> consonant = re.compile('|'.join([guttural , palatal , cerebral ,
> dental , semivowel , sibilant , aspirant]))
>
> print consonant
> print t_NAME
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>
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Re: [Q] How to ignore the first line of the text read from a file

[Marc 'BlackJack' Rintsch]

On Thu, 28 Aug 2008 10:16:45 -0700, norseman wrote:

> Benjamin Kaplan wrote:
>> On Thu, Aug 28, 2008 at 12:11 AM, [EMAIL PROTECTED] <
>> [EMAIL PROTECTED]> wrote:
>> 
>>> Hello,
>>>
>>> I am new to Python and have one simple question to which I cannot find
>>> a satisfactory solution.
>>> I want to read text line-by-line from a text file, but want to ignore
>>> only the first line. I know how to do it in Java (Java has been my
>>> primary language for the last couple of years) and following is what I
>>> have in Python, but I don't like it and want to learn the better way
>>> of doing it.
>>>
>>> file = open(fileName, 'r')
>>> lineNumber = 0
>>> for line in file:
>>>if lineNumber == 0:
>>>lineNumber = lineNumber + 1
>>>else:
>>>lineNumber = lineNumber + 1
>>>print line
>>>
>>> Can anyone show me the better of doing this kind of task?
>>>
>>> Thanks in advance.
>>>
>>> --
>> 
>> 
>> Files are iterators, and iterators can only go through the object once.
>> Just call next() before going in the for loop. Also, don't use "file"
>> as a variable name. It covers up the built-in type.
>> 
>> afile = open(file_name, 'r')
>> afile.next() #just reads the first line and doesn't do anything with it
>> for line in afile :
>>print line
>> 
>> 
>>> http://mail.python.org/mailman/listinfo/python-list
>>>
>>>
>> 
>> 

>> 
>> --
>> http://mail.python.org/mailman/listinfo/python-list
> 
> ==
> actually:
> import os
> 
> file = open(filename, 'r')
> for line in file:
>dummy=line
>for line in file:
>  print line
> 
> 
> is cleaner and faster.

That's not cleaner, that's a 'WTF?'!  A ``for`` line over `file` that 
does *not* iterate over the file but is just there to skip the first line 
and a completely useless `dummy` name.  That's seriously ugly and 
confusing.

Ciao,
Marc 'BlackJack' Rintsch
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Re: file data to list

[Emile van Sebille]

Anish Chapagain wrote:

Hi!!
I am facing problem for extracting file data to the list so as to have
graph plotted through list.
my file(eg: data.txt) is having data like this,

cnt0001a 29000 xretya 01
cnt0002a 29850 brishal 02
cnt0003a 31250 kristal 03

from here, I need to copy data 29000, 29850, 31250 into a single list
and
01, 02, 03 to another so as to plot graph using these value.



data = zip(*[xx.split() for xx in open('data.txt').read().split("\n")])

...assuming newline separators...

...and only 'cuz I like this about zip...

Emile




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Re: List of modules available for import inside Python?

[mblume]

Am Thu, 28 Aug 2008 11:23:01 -0700 schrieb Jason Scheirer:
> 
> I like to direct new users to pydoc's built-in HTTP server:
> 
> import pydoc
> pydoc.gui()
> (then click the 'open browser' button)
>

Now, this is cool !

Thanks a lot!

Martin

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Re: filter in for loop

[Matthew Woodcraft]

GHZ <[EMAIL PROTECTED]> writes:

> I would like to say something like:
>
> for filename in os.listdir(DIR) if filename[-4:] == '.xml':
> 
>
>
> instead of having to say:
>
> for filename in os.listdir(DIR):
> if filename[-4:] == '.xml':
> 

If the reason you don't like this one is the extra indentation, one
possibility is

for filename in os.listdir(DIR):
if filename[-4:] != '.xml':
continue


-M-
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Re: filter in for loop

[Emile van Sebille]

Jerry Hill wrote:

On Thu, Aug 28, 2008 at 6:20 AM, GHZ <[EMAIL PROTECTED]> wrote:

is there a shortcut I'm missing?




import glob

Emile

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Re: Python svn bindings for Subversion?

[Rob Wolfe]

Mike B <[EMAIL PROTECTED]> writes:

> I'm trying to get Subversion 'hook scripts' working on an Ubuntu box and the
> following fails.
>
> from svn import fs, repos, core, delta
>
> As far as I can tell there are two Python Subversion libraries, 'pysvn' and
> 'svn':
> 'pysvn' from http://pysvn.tigris.org/ appears to be a client side interface 
> and
> isn't what I need.
> 'svn' appears to be a SWIG wrapper and could be what I'm looking for, but I
> cannot find it anywhere.
>
> Can anyone point me in the right direction.

Check this:
http://svn.collab.net/repos/svn/trunk/subversion/bindings/swig/python/

HTH,
Rob
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Re: Python svn bindings for Subversion?

[Matthew Woodcraft]

Mike B writes:
> I'm trying to get Subversion 'hook scripts' working on an Ubuntu box and the
> following fails.
>
> from svn import fs, repos, core, delta
[...]
> 'svn' appears to be a SWIG wrapper and could be what I'm looking for, but I
> cannot find it anywhere.
>
> Can anyone point me in the right direction.


It's maintained as part of the main Subversion distribution.

http://svn.collab.net/viewvc/svn/trunk/subversion/bindings/swig/

In Ubuntu, it should be in the python-subversion package.

-M-
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Negative regular expressions (searching for "i" not inside command)

[Bart Kastermans]

I have a file in which I am searching for the letter "i" (actually
a bit more general than that, arbitrary regular expressions could
occur) as long as it does not occur inside an expression that matches
\\.+?\b (something started by a backslash and including the word that
follows).

More concrete example, I have the string "\sin(i)" and I want to match
the argument, but not the i in \sin.

Can this be achieved by combining the regular expressions?  I do not
know the right terminology involved, therefore my searching on the
Internet has not led to any results.

I can achieve something like this by searching for all i and then
throwing away those i that are inside such expressions.  I am now just
wondering if these two steps can be combined into one.

Best,
Bart
-- 
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Re: Syntax error in ".py" file and globals variable values not available.

[Timothy Grant]

On Thu, Aug 28, 2008 at 1:40 AM, Alexis Boutillier
<[EMAIL PROTECTED]> wrote:
> Timothy Grant a écrit :
>>
>> On Wed, Aug 27, 2008 at 2:49 AM, Alexis Boutillier
>> <[EMAIL PROTECTED]> wrote:
>>>
>>> Hi,
>>>
>>> I have a strange behaviour of python with pdb and import statement.
>>> Here is the example code :
>>>
>>> file my1.py:
>>> import my2
>>>
>>> file my2.py:
>>> a=5
>>> toto
>>>
>>> I intentionnaly put a syntax error in file my2.py.
>>>
>>> If I run "python -i my2.py" and run pdb I got :
>>> NameError: name 'toto' is not defined
>>
>> import pdb
>> pdb.pm()
>>>
>>> -> toto
>>
>> print a
>>>
>>> 5
>>>
>>> If I run "python -i my1.py" and run pdb I got :
>>> NameError: name 'toto' is not defined
>>
>> import pdb
>> pdb.pm()
>>>
>>> -> toto
>>
>> print a
>>>
>>> None
>>>
>>> Why can't I get access to variable a in pdb when the process generating
>>> the
>>> error came from an import statement ?
>>>
>>> With python 2.3.5, it works fine and in the two cases I get the correct
>>> value of 5 for variable "a".
>>> with python 2.43,2.5.1,2.5.2, it doesn't work and I get "None" value for
>>> variable a.
>>>
>>> Somebody can explain me this behaviour ?
>>>
>>>
>>> Thanks.
>>> --
>>> Boutillier Alexis
>>> Methodology engineer
>>>
>>> Arteris SA
>>> The Network-on-Chip Company TM
>>> www.arteris.net
>>>
>>> 6 par Ariane Immeuble Mercure
>>> 78284 Guyancourt Cedex
>>> France
>>> Office: (+33) 1 61 37 38 71
>>> Fax:(+33) 1 61 37 38 41
>>> [EMAIL PROTECTED]
>>> --
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>>>
>>
>>
>> Because of the syntax error the module wasn't loaded.
>>
>> What kind of behaviour would you expect on code that has been flagged
>> as not executable?
>>
> I got the same behaviour with :
> file my2.py:
> a=5
> raise SystemError,""
>
> In pdb, I can't have the value of attribute a.
> So this is not linked to the fact that it is a SyntaxError or a SystemError.
>
> I expect to be able to have the value of all attributes that have been used
> before the error occured.
> This is problematic because in a more complicated code, you can't have the
> value of the attribute that was used before the error occured.
> Python know that this attribute exist, it only don't have its value. other
> attribute affected are : __name__,__doc__,__file__.
>
> --
> Boutillier Alexis
> Methodology engineer
>
> Arteris SA
> The Network-on-Chip Company TM
> www.arteris.net
>
> 6 par Ariane Immeuble Mercure
> 78284 Guyancourt Cedex
> France
> Office: (+33) 1 61 37 38 71
> Fax:(+33) 1 61 37 38 41
> [EMAIL PROTECTED]
> --
> http://mail.python.org/mailman/listinfo/python-list
>

So if you were writing C code and the file failed to compile you would
still expect to have a working executable that just worked up until
the point of the syntax error?

I'm not sure why you just don't fix the syntax error and move on.


-- 
Stand Fast,
tjg. [Timothy Grant]
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Re: Descriptor leak in python 2.4 subprocess module

[Michel Lespinasse]

On Thu, Aug 28, 2008 at 10:37:48AM +0100, Tim Golden wrote:
> Michel Lespinasse wrote:
> >I hit an issue with the following python code:
> >try:
> >get_orient = subprocess.Popen (['jpegexiforient', '-n', pathfull],
> >   stdin = subprocess.PIPE,
> >   stdout = subprocess.PIPE)
> >orient = get_orient.communicate ()[0]
> >except:
> >orient = None
> >
> >The application worked fine on my devel machine but I noticed that on a
> >different host, it crashed due to running out of file descriptors.
> >After investigation I found out that the above code was responsible,
> >leaking two file descriptors per invocation if jpegexiforient is not
> >installed on the host.
> 
> This looks like a duplicate of http://bugs.python.org/issue3210.
> Can you confirm if this seems likely (and, if so, perhaps add
> a note to the bug indicating that the problem is on Linux as well)?

The root cause is different (subprocess has separate implementations
for windows and posix), but the issues are similar. In the posix case,
I only observed the issue when you using subprocess.PIPE

The attached patch against subprocess.py (as shipped on debian etch,
based on python version 2.4.4) seems to work for me:

--- /usr/lib/python2.4/subprocess.py2008-04-16 10:59:00.0 -0700
+++ subprocess.py   2008-08-28 13:09:50.0 -0700
@@ -970,6 +970,12 @@
 data = os.read(errpipe_read, 1048576) # Exceptions limited to 1 MB
 os.close(errpipe_read)
 if data != "":
+if p2cwrite:
+os.close(p2cwrite)
+if c2pread and c2pread not in (p2cwrite,):
+os.close(c2pread)
+if errread and errread not in (p2cwrite, c2pread):
+os.close(errread)
 os.waitpid(self.pid, 0)
 child_exception = pickle.loads(data)
 raise child_exception

I've not tested it much, only wrote it a few minutes ago after looking at
the bug you mentionned made me realize that the subprocess module is
actually written in python so I could try and fix it :)

Hope this helps,

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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Re: Negative regular expressions (searching for "i" not inside command)

[Guilherme Polo]

On Thu, Aug 28, 2008 at 5:04 PM, Bart Kastermans
<[EMAIL PROTECTED]> wrote:
> I have a file in which I am searching for the letter "i" (actually
> a bit more general than that, arbitrary regular expressions could
> occur) as long as it does not occur inside an expression that matches
> \\.+?\b (something started by a backslash and including the word that
> follows).
>
> More concrete example, I have the string "\sin(i)" and I want to match
> the argument, but not the i in \sin.
>
> Can this be achieved by combining the regular expressions?  I do not
> know the right terminology involved, therefore my searching on the
> Internet has not led to any results.

Try searching again with the "lookahead" term, or "negative lookahead".

>
> I can achieve something like this by searching for all i and then
> throwing away those i that are inside such expressions.  I am now just
> wondering if these two steps can be combined into one.
>
> Best,
> Bart
> --
> http://www.bartk.nl/
> --
> http://mail.python.org/mailman/listinfo/python-list
>



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