ANN: Veusz 0.5 - a scientific plotting package
Veusz 0.5 - Velvet Ember Under Sky Zenith - http://home.gna.org/veusz/ Veusz is Copyright (C) 2003-2005 Jeremy Sanders [EMAIL PROTECTED] Licenced under the GPL (version 2 or greater) Veusz is a scientific plotting package written in Python (currently 100% Python). It uses PyQt for display and user-interfaces, and numarray for handling the numeric data. Veusz is designed to produce publication-ready Postscript output. Veusz provides a GUI, command line and scripting interface (based on Python) to its plotting facilities. The plots are built using an object-based system to provide a consistent interface. Changes from 0.4: Installation: * distutils used to install the package. RPMS available. Plotting: * Different error bar styles (diamond, curve...) * Matched axes, with the same scale on each * Data can be linked from external files instead of embedded in document * Filled regions under/over functions or xy plots * Improved function clipping near edge of plot * Default values can be set for settings, which are remembered between sessions (e.g. blue points for xy3). * Rotated text labels * Improved fitting, giving results from chi2, etc.. UI: * Can move around widgets and delete them * Exception dump dialog to send bug reports * Improved import dialog help * Propagate settings between widgets * Window positions are saved between sessions Reading data: * Better error handling when reading data + Numerous bug fixes Features of package: * X-Y plots (with errorbars) * Stepped plots (for histograms) * Line plots * Function plots * Fitting functions to data * Stacked plots and arrays of plots * Plot keys * Plot labels * LaTeX-like formatting for text * EPS output * Simple data importing * Scripting interface * Save/Load plots To be done: * Contour plots * Images * UI improvements * Import filters (for qdp and other plotting packages, fits, csv) * Data manipulation * Python embedding interface (for embedding Veusz in other programs). [some of the external interface is complete] Requirements: Python (probably 2.3 or greater required) http://www.python.org/ Qt (free edition) http://www.trolltech.com/products/qt/ PyQt (SIP is required to be installed first) http://www.riverbankcomputing.co.uk/pyqt/ http://www.riverbankcomputing.co.uk/sip/ numarray http://www.stsci.edu/resources/software_hardware/numarray Microsoft Core Fonts (recommended) http://corefonts.sourceforge.net/ For documentation on using Veusz, see the Documents directory. The manual is in pdf, html and text format (generated from docbook). If you enjoy using Veusz, I would love to hear from you. Please join the mailing lists at https://gna.org/mail/?group=veusz to discuss new features or if you'd like to contribute code. The newest code can always be found in CVS. Cheers Jeremy -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
ANN: Snakelets 1.39 (simple-to-use web app server with dynamic pages)
I'm happy to say that Snakelets 1.39 is available. Snakelets is a very simple-to-use Python web application server. This project provides a built-in threaded web server (so you don't need to set up Apache or another web server), Ypages (HTML+Python language, similar to Java's JSPs) and Snakelets: code-centric page request handlers (similar to Java's Servlets). Snakelets is fully unicode compatible and it's possible to run it from a CD (read-only mode). It's released under the open-source MIT Software license. You can download from http://snakelets.sourceforge.net (go to the SF project site, and then the file section). Recent changes include: - Cleanups of a lot of html - index.sn (snakelet index page) support - session timeout page configurable - cross-webapp user authentication method configurable - works on Python 2.4.1 (contains workaround for codec.readline bug) - fixed possible session cookie issues - 'manage' webapp improvements, added vhost config page Note: you need to update your Plugin package too. The old versions won't run anymore. To start, edit the vhost config file (see docs) and then run the serv.py script, or the monitor.py script if you want to start it as a daemon (on Unix). Enjoy, --Irmen de Jong. P.S. if you want to see it in action, visit www.promozilla.nl (the site is all Dutch though) -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
RE: pre-PEP: Suite-Based Keywords - syntax proposal
Bengt Richter wrote: The '::' unary suite operator should return an ordered dict subtype representing the bindings Why ordered? Robert Brewer MIS Amor Ministries [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Suite-Based Keywords
Take a look at Nick Coglan's with proposal: http://groups.google.co.uk/groups?selm=mailman.403.1105274631.22381.python-list%40python.org It addresses many of the same issues (e.g. easy definition of properties). It is more general, though: while your proposal only applies to keyword arguments in a function call this one can be used to name any part of a complex expression and define it in a suite. I think that a good hybrid solution would be to combine the with block with optional use of the ellipsis to mean all names defined in the with block. See also the thread resulting from Andrey Tatarinov's original proposal (using the keyword where): http://groups.google.co.uk/groups?selm=3480qqF46jprlU1%40individual.net Oren -- http://mail.python.org/mailman/listinfo/python-list
Decorator Syntax For Recursive Properties
Consider the following class: class Node(object): def __init__(self, name, parent=None): self.name = name self.parent = parent def _ancestors(self, ants=None): if ants is None: ants = [] else: ants.insert(0, self.name) if self.parent is None: return ants return self.parent._ancestors(ants) ancestors = property(_ancestors) The ancestor property generates a list ancestor nodes by having each parent examine its own name recursively. The recursion is managed by calling the method underlying the parent property, rather than calling the property directly. Is it possible to rewrite this property using decorator syntax? Does the @property decorator create some underlying method that I can call directly? Alternately, perhaps there is a way to rewrite the recursion so that such a call is unnecessary? Note that the property should not add its own name if it is the originating node (the node trying to find _its_ ancestors). So something like this didn't work for me: @property def ancestors(self): if self.parent is None: return [self.name] return [self.name] + self.parent.ancestors In other words, since there is no longer a list passing from child to parent during the recursion, is there a graceful way to examine the state of the ancestor list so far? Thanks, Jeffrey -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
On Sat, 16 Apr 2005 17:25:00 -0700, Brian Sabbey
[EMAIL PROTECTED] wrote:
You can already do this, this way.
def f(thunk):
... before()
... thunk()
... after()
...
def before():
... print 'before'
...
def after():
... print 'after'
...
def stuff():
... print 'stuff'
...
def morestuff():
... print 'morestuff'
...
f(stuff)
before
stuff
after
f(morestuff)
before
morestuff
after
This works with arguments also.
Yes, much of what thunks do can also be done by passing a function
argument. But thunks are different because they share the surrounding
function's namespace (which inner functions do not), and because they can
be defined in a more readable way.
Generally my reason for using a function is to group and separate code
from the current name space. I don't see that as a drawback.
Are thunks a way to group and reuse expressions in the current scope?
If so, why even use arguments? Wouldn't it be easier to just declare
what I need right before calling the group? Maybe just informally
declare the calling procedure in a comment.
def thunkit: # no argument list defines a local group.
# set thunk,x and y before calling.
before()
result = thunk(x,y)
after()
def foo(x,y):
x, y = y, x
return x,y
thunk = foo
x,y = 1,2
do thunkit
print result
- (2,1)
Since everything is in local name space, you really don't need to
pass arguments or return values.
The 'do' keyword says to evaluate the group. Sort of like eval() or
exec would, but in a much more controlled way. And the group as a
whole can be passed around by not using the 'do'. But then it starts
to look and act like a class with limits on it. But maybe a good
replacement for lambas?
I sort of wonder if this is one of those things that looks like it
could be useful at first, but it turns out that using functions and
class's in the proper way, is also the best way. (?)
You're right that, in this case, it would be better to just write
f(stuff, 27, 28). That example was just an attempt at describing the
syntax and semantics rather than to provide any sort of motivation. If
the thunk contained anything more than a call to 'stuff', though, it would
not be as easy as passing 'stuff' to 'f'. For example,
do f(27, 28):
print stuff()
would require one to define and pass a callback function to 'f'. To me,
'do' should be used in any situation in which a callback *could* be used,
but rarely is because doing so would be awkward. Probably the simplest
real-world example is opening and closing a file. Rarely will you see
code like this:
def with_file(callback, filename):
f = open(filename)
callback(f)
f.close()
def print_file(file):
print file.read()
with_file(print_file, 'file.txt')
For obvious reasons, it usually appears like this:
f = open('file.txt')
print f.read()
f.close()
Normally, though, one wants to do a lot more than just print the file.
There may be many lines between 'open' and 'close'. In this case, it is
easy to introduce a bug, such as returning before calling 'close', or
re-binding 'f' to a different file (the former bug is avoidable by using
'try'/'finally', but the latter is not). It would be nice to be able to
avoid these types of bugs by abstracting open/close. Thunks allow you to
make this abstraction in a way that is more concise and more readable than
the callback example given above:
How would abstracting open/close help reduce bugs?
I'm really used to using function calls, so anything that does things
differently tend to be less readable to me. But this is my own
preference. What is most readable to people tends to be what they use
most. IMHO
do f in with_file('file.txt'):
print f.read()
Thunks are also more useful than callbacks in many cases since they allow
variables to be rebound:
t = no file read yet
do f in with_file('file.txt'):
t = f.read()
Using a callback to do the above example is, in my opinion, more
difficult:
def with_file(callback, filename):
f = open(filename)
t = callback(f)
f.close()
return t
def my_read(f):
return f.read()
t = with_file(my_read, 'file.txt')
Wouldn't your with_file thunk def look pretty much the same as the
callback?
I wouldn't use either of these examples. To me the open/read/close
example you gave as the normal case would work fine, with some basic
error checking of course. Since Python's return statement can handle
multiple values, it's no problem to put everything in a single
function and return both the status with an error code if any, and the
result. I would keep the open, read/write, and close statements in
the same function and not split them up.
When I see 'do', it reminds me of 'do loops'. That is 'Do' involves
some sort of flow control. I gather you mean it as do items in a
list, but with the capability to substitute the named function.
Re: pre-PEP: Suite-Based Keywords - syntax proposal
Robert Brewer wrote: Bengt Richter wrote: The '::' unary suite operator should return an ordered dict subtype representing the bindings Why ordered? Because You can't otherwise guarantee to feed optional argument parameters in a correct way. Example: x = property(*seq) where: seq = (item[1] for item in :: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ) This statement would not work if the result of '::' ( considered as an ordered dict ) would return simply a dict because the order of the input parameters matters. Ciao, Kay -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Tim Roberts wrote at 22:05 4/16/2005: Dick Moores [EMAIL PROTECTED] wrote: # Reading/writing Python source often gives me the impression of # reading/writing a poem! # Layout, indentation, rythm, I like the look and feel! # What does this tiny program do? It is not a sonnet, even not a # pi-sonnet, but it surely produces Pi! It sure does. When I ran it my jaw dropped. I had 7,947 CORRECT digits in 2 minutes 0 seconds (by my stopwatch)! How do you know? I think the 7,912th digit is wrong. ;) I suppose you're joshing, Tim, but I really did check by using my trusty def compareSequences(seq1, seq2): find first index at which two sequences differ if s1 == s2: print Sequences are identical return None if len(seq1) = len(seq2): shorterOrEqualSequence = seq2 else: shorterOrEqualSequence = seq1 for index in range(len(shorterOrEqualSequence)): if seq1[index] != seq2[index]: print sequences first differ at index, index print s1 at that index is, s1[index] print s2 at that index is, s2[index] break if index == len(shorterOrEqualSequence)-1: print sequences are identical thru end of shorter sequence at index, index == I got the correct pi from http://www.ballandclaw.com/upi/pi.5.html. By inspection of the text file I copied this to (removing the 3. of 3.1), the 7,912th digit is 2 (I'm using Textpad). If you begin with 31, which what the speedy script does, the 7,912th digit is 6. Now, I've shown you mine. Show me yours. ;-) Dick -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
On Sat, 16 Apr 2005 18:46:28 -0700, Brian Sabbey [EMAIL PROTECTED] wrote: [...] In that case, my version would just not have a do, instead defining the do suite as a temp executable suite, e.g., if instead we make an asignment in the suite, to make it clear it's not just a calling thing, e.g., do f(27, 28): x = stuff() then my version with explict name callable suite would be def f(thunk, a, b): # a == 27, b == 28 before() thunk() after() set_x(): x = stuff() # to make it plain it's not just a calling thing f(set_x, 27, 28) # x is now visible here as local binding but a suitable decorator and an anonymous callable suite (thunk defined my way ;-) would make this @f(27, 28) (): x = stuff() Hmm, but this would require decorators to behave differently than they do now. Currently, decorators do not automatically insert the decorated function into the argument list. They require you to define 'f' as: def f(a, b): def inner(thunk): before() thunk() after() return inner Having to write this type of code every time I want an thunk-accepting function that takes other arguments would be pretty annoying to me. Yes, I agree. That's the way it is with the decorator expression. Maybe decorator syntax is not the way to pass thunks to a function ;-) My latest thinking is in terms of suite expressions, ::suite being one, and actually (arglist):suite is also a suite expression, yielding a thunk. So the call to f could just be written explicitly with the expression in line: f((():x=stuff()), 27, 28) or f((): x = stuff() done = True ,27, 28) # letting the dedented ',' terminate the ():suite rather than parenthesizing or safe_open((f): for line in f: print f[:20] ,'datafile.txt', 'rb') That's not too bad IMO ;-) Thunks can also accept arguments: def f(thunk): thunk(6,7) do x,y in f(): # x==6, y==7 stuff(x,y) IMO @f (x, y): stuff(x, y) # like def foo(x, y): stuff(x, y) is clearer, once you get used to the missing def foo format OK. I prefer a new keyword because it seems confusing to me to re-use decorators for this purpose. But I see your point that decorators can be used this way if one allows anonymous functions as you describe, and if one allows decorators to handle the case in which the function being decorated is anonymous. I tend to agree now about using decorators for this. With thunk calling parameter and extra f calling parameters, in line would look like f((x,y): # x==6, y==7 stuff(x, y) ,'other' ,'f' ,args) I guess you could make a bound method to keep the thunk dothunk_n_all = f.__get__((x, y): stuff(x,y) ,type(():pass)) and then call that with whatever other parameter you specified for f do_thunk_n_all(whatever) if that seemed useful ;-) The return value can be captured This is just a fallout of f's being an ordinary function right? IOW, f doesn't really know thunk is not an ordinary callable too? I imagine that is for the CALL_FUNCTION byte code implementation to discover? yes def f(thunk): thunk() return 8 do t=f(): # t not bound yet stuff() print t == 8 That can't be done very well with a decorator, but you could pass an explicit named callable suite, e.g., thunk(): stuff() t = f(thunk) But not having to do it that way was most of the purpose of thunks. I forgot that ():suite is an expression t = f(():stuff()) # minimal version or final_status = safe_open((f): for line in f: print f[:20] ,'datafile.txt', 'rb') snip It wouldn't be a problem to use 'return' instead of 'continue' if people so desired, but I find 'return' more confusing because a 'return' in 'for' suites returns from the function, not from the suite. That is, having 'return' mean different things in these two pieces of code would be confusing: for i in [1,2]: return 10 do i in each([1,2]): return 10 But in my syntax, each((i): return 10 ,[1,2]) Um, well, I guess one has to think about it ;-/ The thunk-accepter could pass the thunk a mutable arg to put a return value in, or even a returnvalue verse thunk? def accepter(thk, seq): acquire() for i in seq: thk(i, (retval):pass) if retval: break release() accepter((i, rvt): print i rvt(i==7) # is this legal? , xrange(10)) Hm, one thing my syntax does, I just noticed, is allow you to pass several thunks to a thunk-accepter, if desired, e.g., (parenthesizing this time, rather than ending ():suite with dedented comma) each( ((i): # normal thunk print i), ((j): # alternative thunk rejectlist.append(j)), [1,2]) snip I see what you're
Re: new to mac OS10
Robert Kern wrote: 3. Apple-installed Python's command line tools are symlinked from /usr/bin to /System/Library/Frameworks/Python.framework but the OSX installer for Python 2.4.1 places the commandline tools in /usr/local/bin and symlinked to /Library/Frameworks/Python.framework. So it seems to me that Python 2.4.1 (installed using OSX installer for Python 2.4.1) is not a precise replacement of Apple-installed Python... Bingo. It's not intended to be one. Hi Robert, Once I've tried to install Python 2.4.1 through the installer Bob Ippolito built. I've already for Fink installed Python 2.3.5 in my system. So, /usr/bin/python - /sw/bin/python and the newly installed Python 2.4.1 created /usr/local/bin/python - /Library/Frameworks/Python.framework/python Does /usr/bin/python takes precedence over /usr/local/bin/python? Somehow it rings an alarm in me... Cheers Maurice -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: Python 2.3.2 for PalmOS available
[EMAIL PROTECTED] wrote: Some months ago i did a port of the Python2.3.2 interpreter to PalmOS. I didnt port any C module or created modules for PalmOS API's. Just port ctypes. Then we'll be good to go. wink Seriously, this looks like a cool beginning. -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
M.E.Farmer wrote at 23:18 4/14/2005: Using the GNU bc utility: $ bc -l bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale = 3000# number of output places wanted obase = 12 # output base print 4 * a(1) # pi = 4*arctan(1) Wow! this got me the 3003 (changed from 3000) digits of pi to base 12 in 60.8 secs. No, I didn't count them yet, nor am I sure they're correct. But I'd bet on them.. Could someone remind me how to get the output of bc -l into a text file on Windows? (I've tried employing pi3003.txt in various ways) OR, how to copy and paste from the command line window, or whatever that window is called? (Sorry for the OT question.) BTW I found a nice set of SCO UNIX man pages at http://www.rt.com/man/. Dick -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Suite-Based Keywords
On 16 Apr 2005 23:06:10 -0700, [EMAIL PROTECTED] (Oren Tirosh) wrote: Take a look at Nick Coglan's with proposal: http://groups.google.co.uk/groups?selm=mailman.403.1105274631.22381.python-list%40python.org It addresses many of the same issues (e.g. easy definition of properties). It is more general, though: while your proposal only applies to keyword arguments in a function call this one can be used to name any part of a complex expression and define it in a suite. I think that a good hybrid solution would be to combine the with block with optional use of the ellipsis to mean all names defined in the with block. See also the thread resulting from Andrey Tatarinov's original proposal (using the keyword where): http://groups.google.co.uk/groups?selm=3480qqF46jprlU1%40individual.net Apologies for lack of attibution, Andrey. And I'm not sure I used your where properly just recently. I added it to some other stuff in haste, without actually remembering exactly where it came from, believe it or not, even though I got heavily into it in that thread. Somewhat disturbing memory lapse ;-/ I need some sleep ;-/ Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: whitespace , comment stripper, and EOL converter
There is an issue with both my and your code: it only works if doc
strings are triple quoted and if there are no other triple quoted
strings in the Python code.
A triple quoted string used in an assignment will be removed, for
example this case
s = '''this string should not be removed'''
It is still unclear how to distinguish doc strings from other strings.
Also, I have not checked the precise Python syntax, but doc strings do
not need to be enclosed by triple quotes. A single quote may be
allowed too.
Maybe this rule will work: a doc string is any string preceded by a
COLON token followed by zero, one or more INDENT or NEWLINE tokens.
Untested!
/Jean Brouwers
M.E.Farmer wrote:
Thanks Jean,
I have thought about adding docstrings several times, but I was
stumped
at how to determine a docstring from a regular tripleqoted string ;)
I have been thinking hard about the problem and I think I have an
idea.
If the line has nothing before the start of the string it must be a
docstring.
Sounds simple enough but in Python there are 12 or so 'types' of
strings .
Here is my crack at it feel free to improve it ;)
I reversed the logic on the comments and docstrings so I could add a
special mode to docstring stripping ...pep8 mode .
Pep8 mode only strips double triple quotes from your source code
leaving the offending single triple quotes behind. Probably just
stupid
but someone might find it usefull.
##
# Python source stripper
##
import os
import sys
import token
import keyword
import StringIO
import tokenize
import traceback
__credits__ = '''
Jürgen Hermann
M.E.Farmer
Jean Brouwers
'''
__version__ = '.8'
__author__ = 'M.E.Farmer'
__date__ = 'Apr 16, 2005,' \
'Jan 15 2005,' \
'Oct 24 2004' \
##
class Stripper:
Python source stripper
def __init__(self, raw):
self.raw = raw
def format(self, out=sys.stdout, comments=0, docstrings=0,
spaces=1, untabify=1, eol='unix'):
strip comments,
strip docstrings,
strip extra whitespace and lines,
convert tabs to spaces,
convert EOL's in Python code.
# Store line offsets in self.lines
self.lines = [0, 0]
pos = 0
# Strips the first blank line if 1
self.lasttoken = 1
self.temp = StringIO.StringIO()
self.spaces = spaces
self.comments = comments
self.docstrings = docstrings
if untabify:
self.raw = self.raw.expandtabs()
self.raw = self.raw.rstrip()+' '
self.out = out
# Have you ever had a multiple line ending script?
# They can be nasty so lets get them all the same.
self.raw = self.raw.replace('\r\n', '\n')
self.raw = self.raw.replace('\r', '\n')
self.lineend = '\n'
# Gather lines
while 1:
pos = self.raw.find(self.lineend, pos) + 1
if not pos: break
self.lines.append(pos)
self.lines.append(len(self.raw))
self.pos = 0
# Wrap text in a filelike object
text = StringIO.StringIO(self.raw)
# Parse the source.
## Tokenize calls the __call__
## method for each token till done.
try:
tokenize.tokenize(text.readline, self)
except tokenize.TokenError, ex:
traceback.print_exc()
# Ok now we write it to a file
# but we also need to clean the whitespace
# between the lines and at the ends.
self.temp.seek(0)
# All this should be written into the
# __call__ method just haven't yet...
# Mac CR
if eol == 'mac':
self.lineend = '\r'
# Windows CR LF
elif eol == 'win':
self.lineend = '\r\n'
# Unix LF
else:
self.lineend = '\n'
for line in self.temp.readlines():
if spaces == -1:
self.out.write(line.rstrip()+self.lineend)
else:
if not line.isspace():
self.lasttoken=0
self.out.write(line.rstrip()+self.lineend)
else:
self.lasttoken+=1
if self.lasttoken=self.spaces and self.spaces:
self.out.write(self.lineend)
def __call__(self, toktype, toktext,
(srow,scol), (erow,ecol), line):
Token handler.
# calculate new positions
oldpos = self.pos
newpos = self.lines[srow] + scol
self.pos = newpos + len(toktext)
# kill comments
if self.comments:
if toktype ==
Re: pre-PEP: Suite-Based Keywords - syntax proposal
On 16 Apr 2005 23:43:03 -0700, Kay Schluehr [EMAIL PROTECTED] wrote: Robert Brewer wrote: Bengt Richter wrote: The '::' unary suite operator should return an ordered dict subtype representing the bindings Why ordered? Because You can't otherwise guarantee to feed optional argument parameters in a correct way. Example: x = property(*seq) where: seq = (item[1] for item in :: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ) This statement would not work if the result of '::' ( considered as an ordered dict ) would return simply a dict because the order of the input parameters matters. Exactly. Except the above example is from the day-old-bread items-tuple-returning version of :: ;-) And with an ordered dict subtype there is no need for the generator expression either, since there is a values method for dicts (which in the subtype would preserve order). E.g., x = property(*seq) where: seq = (:: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ).values()) Or more directly: x = property(*(:: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ).values()) Or eliminating parens by using dedent to end the :: suite: x = property(*:: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. .values()) Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: new to mac OS10
Maurice LING wrote: Robert Kern wrote: 3. Apple-installed Python's command line tools are symlinked from /usr/bin to /System/Library/Frameworks/Python.framework but the OSX installer for Python 2.4.1 places the commandline tools in /usr/local/bin and symlinked to /Library/Frameworks/Python.framework. So it seems to me that Python 2.4.1 (installed using OSX installer for Python 2.4.1) is not a precise replacement of Apple-installed Python... Bingo. It's not intended to be one. Hi Robert, Once I've tried to install Python 2.4.1 through the installer Bob Ippolito built. I've already for Fink installed Python 2.3.5 in my system. So, /usr/bin/python - /sw/bin/python Don't do that. Leave /usr alone! (/usr/local excepted) Change your PATH environment variable if you want a different Python to start up when you type $ python and the newly installed Python 2.4.1 created /usr/local/bin/python - /Library/Frameworks/Python.framework/python Does /usr/bin/python takes precedence over /usr/local/bin/python? Somehow it rings an alarm in me... That depends on your PATH environment variable, and that only affects the command line in a terminal shell. Anything that looks for /usr/bin/python should find the link to the system Python. Anything that just asks for whatever python comes first in your PATH is customizable via the order of directories in your PATH. -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Dick Moores wrote: M.E.Farmer wrote at 23:18 4/14/2005: Using the GNU bc utility: $ bc -l bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale = 3000# number of output places wanted obase = 12 # output base print 4 * a(1) # pi = 4*arctan(1) Wow! this got me the 3003 (changed from 3000) digits of pi to base 12 in 60.8 secs. No, I didn't count them yet, nor am I sure they're correct. But I'd bet on them.. Could someone remind me how to get the output of bc -l into a text file on Windows? (I've tried employing pi3003.txt in various ways) OR, how to copy and paste from the command line window, or whatever that window is called? (Sorry for the OT question.) Works for me (using the Cygwin version though) when I do C:\cygwin\bin\bc -l pi12.txt Otherwise, to copy from the command prompt window: open the system menu (icon in the top left corner of the window) and choose Edit-Mark. Then select what you want to copy and press Enter or choose Edit-Copy in the system menu. -- If I have been able to see further, it was only because I stood on the shoulders of giants. -- Isaac Newton Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
Ron_Adam wrote: I sort of wonder if this is one of those things that looks like it could be useful at first, but it turns out that using functions and class's in the proper way, is also the best way. (?) I think Your block is more low level. It is like copying and pasting code-fragments together but in reversed direction: if You copy and paste a code fragment and wants to change the behaviour You probable have to change the fragment the same way in every place of occurence. This is a well known anti-pattern in software construction. If You change Your thunk somehow e.g. from def yield_thunk: yield i to def yield_thunk: yield j You have to change all the environments that use the thunk e.g. renaming variables. It is the opposite direction of creating abstractions i.e. a method to deabstract functions: introduce less modularity and more direct dependencies. This is the reason why those macros are harmfull and should be abandoned from high level languages ( using them in C is reasonable because code expansion can be time efficient and it is also a way to deal with parametric polymorphism but Python won't benefit from either of this issues ). Ciao, Kay -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
On Sun, 17 Apr 2005 01:00:46 -0700, Dick Moores [EMAIL PROTECTED] wrote: M.E.Farmer wrote at 23:18 4/14/2005: Using the GNU bc utility: $ bc -l bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale = 3000# number of output places wanted obase = 12 # output base print 4 * a(1) # pi = 4*arctan(1) Wow! this got me the 3003 (changed from 3000) digits of pi to base 12 in 60.8 secs. No, I didn't count them yet, nor am I sure they're correct. But I'd bet on them.. Could someone remind me how to get the output of bc -l into a text file on Windows? (I've tried employing pi3003.txt in various ways) OR, how to copy and paste from the command line window, or whatever that window is called? (Sorry for the OT question.) To copy from the command window to the clipboard: 1. Scroll top of desired stuff to make it visible near top 2. Hold down Alt 3. Tap Space Bar 4. Release Alt 5. Tap e 6. Tap k 7. Use mouse or arrow keys to place cursor on top left corner of desired box 8. Hold down Shift 9. Use arrow keys or mouse-with-left-button-pressed to go to bottom right character of desired box 9a. If the bottom is out of sight, keep holding shift down and pretend you can cursor down below bottom. the attempt should make the screen scroll up and select more desired material. If you overshoot, don't panic, just keep holding down shift and use arrows (the are slower) or mouse-with-left-button-still-down to move to desired bottom right corner. 10. Release mouse button if using that 11. Release Shift 12. Press Enter That should copy to the clipboard and make the selection box revert to normal display. Pasting from clipboard is up to you. Pasting into the command window from clipboard is 2-5 above, and Tap p HTH PS. Redirecting with from a script whose interpreter was started by windows extension association doesn't work on some version of windows. To be safe, invoke the interpreter explicitly, e.g., python myscript.py [whatever args here] pi3003.txt If myscript.py is not in the current directory, use a sufficient path to it. If your windows is having that problem, the same will happen with a perl script or other script when you run it as just myscript.ext ... and depend on windows to start the right interpreter. Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Roel Schroeven wrote at 01:45 4/17/2005: Dick Moores wrote: M.E.Farmer wrote at 23:18 4/14/2005: Using the GNU bc utility: $ bc -l bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale = 3000# number of output places wanted obase = 12 # output base print 4 * a(1) # pi = 4*arctan(1) Wow! this got me the 3003 (changed from 3000) digits of pi to base 12 in 60.8 secs. No, I didn't count them yet, nor am I sure they're correct. But I'd bet on them.. Could someone remind me how to get the output of bc -l into a text file on Windows? (I've tried employing pi3003.txt in various ways) OR, how to copy and paste from the command line window, or whatever that window is called? (Sorry for the OT question.) Works for me (using the Cygwin version though) when I do C:\cygwin\bin\bc -l pi12.txt But how or when do you enter the lines scale = 3000 obase = 12 print 4 * a(1) Otherwise, to copy from the command prompt window: open the system menu (icon in the top left corner of the window) and choose Edit-Mark. Then select what you want to copy and press Enter or choose Edit-Copy in the system menu. Thanks! You've just relieved years of frustration. Dick -- http://mail.python.org/mailman/listinfo/python-list
Re: whitespace , comment stripper, and EOL converter
MrJean1 wrote:
There is an issue with both my and your code: it only works if doc
strings are triple quoted and if there are no other triple quoted
strings in the Python code.
I had not considered single quoted strings ;)
A triple quoted string used in an assignment will be removed, for
example this case
s = '''this string should not be removed'''
It is still unclear how to distinguish doc strings from other
strings.
Also, I have not checked the precise Python syntax, but doc strings
do
not need to be enclosed by triple quotes. A single quote may be
allowed too.
Maybe this rule will work: a doc string is any string preceded by a
COLON token followed by zero, one or more INDENT or NEWLINE tokens.
Untested!
Not needed , if you reread my post I explain that I had solved that
issue.
If you use the line argument that tokenizer supplies we can strip
whitespace and 'rRuU' from the start of the line and look for a single
quote or a double quote .
I have tested it and it works.
Reworked the 'pep8' thing and fixed the bug you mentioned here is the
changes.
##
# Python source stripper
##
import os
import sys
import token
import keyword
import StringIO
import tokenize
import traceback
__credits__ = '''
Jürgen Hermann
M.E.Farmer
Jean Brouwers
'''
__version__ = '.8'
__author__ = 'M.E.Farmer'
__date__ = 'Apr 16, 2005,' \
'Jan 15 2005,' \
'Oct 24 2004' \
##
class Stripper:
Python source stripper
def __init__(self, raw):
self.raw = raw
def format(self, out=sys.stdout, comments=0, docstrings=0,
spaces=1, untabify=1, eol='unix'):
strip comments,
strip docstrings,
strip extra whitespace and lines,
convert tabs to spaces,
convert EOL's in Python code.
# Store line offsets in self.lines
self.lines = [0, 0]
pos = 0
# Strips the first blank line if 1
self.lasttoken = 1
self.temp = StringIO.StringIO()
self.spaces = spaces
self.comments = comments
self.docstrings = docstrings
if untabify:
self.raw = self.raw.expandtabs()
self.raw = self.raw.rstrip()+' '
self.out = out
# Have you ever had a multiple line ending script?
# They can be nasty so lets get them all the same.
self.raw = self.raw.replace('\r\n', '\n')
self.raw = self.raw.replace('\r', '\n')
self.lineend = '\n'
# Gather lines
while 1:
pos = self.raw.find(self.lineend, pos) + 1
if not pos: break
self.lines.append(pos)
self.lines.append(len(self.raw))
self.pos = 0
# Wrap text in a filelike object
text = StringIO.StringIO(self.raw)
# Parse the source.
## Tokenize calls the __call__
## method for each token till done.
try:
tokenize.tokenize(text.readline, self)
except tokenize.TokenError, ex:
traceback.print_exc()
# Ok now we write it to a file
# but we also need to clean the whitespace
# between the lines and at the ends.
self.temp.seek(0)
# All this should be written into the
# __call__ method just haven't yet...
# Mac CR
if eol == 'mac':
self.lineend = '\r'
# Windows CR LF
elif eol == 'win':
self.lineend = '\r\n'
# Unix LF
else:
self.lineend = '\n'
for line in self.temp.readlines():
if spaces == -1:
self.out.write(line.rstrip()+self.lineend)
else:
if not line.isspace():
self.lasttoken=0
self.out.write(line.rstrip()+self.lineend)
else:
self.lasttoken+=1
if self.lasttoken=self.spaces and self.spaces:
self.out.write(self.lineend)
def __call__(self, toktype, toktext,
(srow,scol), (erow,ecol), line):
Token handler.
# calculate new positions
oldpos = self.pos
newpos = self.lines[srow] + scol
self.pos = newpos + len(toktext)
# kill comments
if self.comments:
if toktype == tokenize.COMMENT:
return
# kill doc strings
if self.docstrings:
# Assume if there is nothing on the
# left side it must be a docstring
if toktype ==
Pattern Matching Given # of Characters and no String Input; use RegularExpressions?
Hello, Can regular expressions compare file names to one another. It seems RE can only compare with input i give it, while I want it to compare amongst itself and give me matches if the first x characters are similiar. For example: cccat cccap cccan dddfa dddfg dddfz Would result in the 'ddd' and the 'ccc' being grouped together if I specified it to look for a match of the first 3 characters. What I am trying to do is build a script that will automatically create directories based on duplicates like this starting with say 10 characters, and going down to 1. This way Vacation1.jpg, Vacation2.jpg would be sent to its own directory (if i specifiy the first 8 characters being similiar) and Cat1.jpg, Cat2.jpg would (with 3) as well. Thanks for your help and interest! S M -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Dick Moores [EMAIL PROTECTED] writes: C:\cygwin\bin\bc -l pi12.txt But how or when do you enter the lines scale = 3000 obase = 12 print 4 * a(1) You could put them into a file, say pi.bc. Then run bc -l pi.bc -- http://mail.python.org/mailman/listinfo/python-list
Re: whitespace , comment stripper, and EOL converter
Google has now 'fixed' there whitespace issue and now has an auto-quote issue argggh! The script is located at: http://bellsouthpwp.net/m/e/mefjr75/python/stripper.py M.E.Farmer -- http://mail.python.org/mailman/listinfo/python-list
Re: Pattern Matching Given # of Characters and no String Input; use RegularExpressions?
Synonymous wrote: Can regular expressions compare file names to one another. It seems RE can only compare with input i give it, while I want it to compare amongst itself and give me matches if the first x characters are similiar. Do you have to use regular expressions? If you know the number of characters to match can't you just compare slices? In [1]: f1,f2='cccat','cccap' In [2]: f1[:3] Out[2]: 'ccc' In [3]: f1[:3]==f2[:3] Out[3]: True It seems to me you just have to compare each file to the next one (after having sorted your list). -- http://mail.python.org/mailman/listinfo/python-list
Re: Pattern Matching Given # of Characters and no String Input; use RegularExpressions?
tiissa wrote:
If you know the number of characters to match can't you just compare
slices?
If you don't, you can still do it by hand:
In [7]: def cmp(s1,s2):
: diff_map=[chr(s1[i]!=s2[i]) for i in range(min(len(s1),
len(s2)))]
: diff_index=''.join(diff_map).find(chr(True))
: if -1==diff_index:
: return min(len(s1), len(s2))
: else:
: return diff_index
:
In [8]: cmp('cccat','cccap')
Out[8]: 4
In [9]: cmp('ccc','cccap')
Out[9]: 3
In [10]: cmp('cccat','dddfa')
Out[10]: 0
--
http://mail.python.org/mailman/listinfo/python-list
Re: XML parsing per record
William Park wrote: You may want to try Expat (www.libexpat.org) or Python wrapper to it. Python comes with a low-level expat wrapper (pyexpat). however, if you want performance, cElementTree (which also uses expat) is a lot faster than pyexpat. (see my other post for links to benchmarks and code). /F -- http://mail.python.org/mailman/listinfo/python-list
Re: Pattern Matching Given # of Characters and no String Input; useRegularExpressions?
tiissa wrote: Synonymous wrote: Can regular expressions compare file names to one another. It seems RE can only compare with input i give it, while I want it to compare amongst itself and give me matches if the first x characters are similiar. Do you have to use regular expressions? If you know the number of characters to match can't you just compare slices? It seems to me you just have to compare each file to the next one (after having sorted your list). itertools.groupby() can do the comparing and grouping: import itertools def groupbyPrefix(lst, n): ... lst.sort() ... def key(item): ... return item[:n] ... return [ list(items) for k, items in itertools.groupby(lst, key=key) ] ... names = ['cccat', 'cccap', 'cccan', 'cccbt', 'ccddd', 'dddfa', 'dddfg', 'dddfz'] groupbyPrefix(names, 3) [['cccat', 'cccap', 'cccan', 'cccbt'], ['ccddd'], ['dddfa', 'dddfg', 'dddfz']] groupbyPrefix(names, 2) [['cccat', 'cccap', 'cccan', 'cccbt', 'ccddd'], ['dddfa', 'dddfg', 'dddfz']] Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Bengt Richter wrote at 02:26 4/17/2005: Could someone remind me how to get the output of bc -l into a text file on Windows? (I've tried employing pi3003.txt in various ways) OR, how to copy and paste from the command line window, or whatever that window is called? (Sorry for the OT question.) To copy from the command window to the clipboard: 1. Scroll top of desired stuff to make it visible near top 2. Hold down Alt 3. Tap Space Bar 4. Release Alt 5. Tap e 6. Tap k 7. Use mouse or arrow keys to place cursor on top left corner of desired box 8. Hold down Shift 9. Use arrow keys or mouse-with-left-button-pressed to go to bottom right character of desired box 9a. If the bottom is out of sight, keep holding shift down and pretend you can cursor down below bottom. the attempt should make the screen scroll up and select more desired material. If you overshoot, don't panic, just keep holding down shift and use arrows (the are slower) or mouse-with-left-button-still-down to move to desired bottom right corner. 10. Release mouse button if using that 11. Release Shift 12. Press Enter That should copy to the clipboard and make the selection box revert to normal display. Pasting from clipboard is up to you. Pasting into the command window from clipboard is 2-5 above, and Tap p Thanks for showing me another way. But Roel Schroeven's to copy from the command prompt window: open the system menu (icon in the top left corner of the window) and choose Edit-Mark. Then select what you want to copy and press Enter or choose Edit-Copy in the system menu. seems to be easier. PS. Redirecting with from a script whose interpreter was started by windows extension association doesn't work on some version of windows. To be safe, invoke the interpreter explicitly, e.g., python myscript.py [whatever args here] pi3003.txt Thanks very much for this. What kind of args could I use here? Dick -- http://mail.python.org/mailman/listinfo/python-list
module to parse pseudo natural language?
Hi all I've written a python program that adds orders into our order routing simulation system. It works well, and has a syntax along these lines: ./neworder --instrument NOKIA --size 23 --price MARKET --repeats 20 etc However, I'd like to add a mode that will handle, say: ./neworder buy 23 NOKIA at MKT x 20 I could enter several orders either by running multiple times, or use a comma-separated approach, like: ./neworder buy 23 NOKIA at MKT on helsinki, sell 20 NOKIA at market on helsinki The thing about this is that its a tolerant parser, so all of these should also work: # omit words like at, on ./neworder buy 23 NOKIA mkt helsinki # take any symbol for helsinki ./neworder buy 23 mkt helsinki # figure out that market=helsinki ./neworder buy 23 NOKIA at market price I've started writing a simple state-based parser, usage like: class NaturalLanguageInsructionBuilder: def parse( self, arglist ): Given a sequence of args, return an Instruction object ... return Instruction( instrument, size, price, ... ) class Instruction: encapsulate a single instruction to buy, sell, etc def __init__( self, instrument, size, price, ... ): ... This doesn't work yet, but I know with time I'll get there. Question is - is there a module out there that will already handle this approach? Thanks for any suggestions :) Andrew -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
Paul Rubin wrote at 02:35 4/17/2005: Dick Moores [EMAIL PROTECTED] writes: C:\cygwin\bin\bc -l pi12.txt But how or when do you enter the lines scale = 3000 obase = 12 print 4 * a(1) You could put them into a file, say pi.bc. Then run bc -l pi.bc OK, now that I've got Textpad trained to open .bc files, I'm thinking of things to store in them. I'm sure I'll want to put in some remarks as well. What should I use to mark the remarks. #, //, or what? The bc man page at http://www.rt.com/man/bc.1.html is tough. Any suggestion for more easily understandable help? And finally (maybe), is it possible to employ bc within a Python script? Thanks, Dick -- http://mail.python.org/mailman/listinfo/python-list
Re: [perl-python] Python documentation moronicities (continued)
# [EMAIL PROTECTED] / 2005-04-13 08:07:06 +1000:
On Tue, 12 Apr 2005 13:06:36 +0200, Roman Neuhauser
[EMAIL PROTECTED] wrote:
Unfortunately, the python community seems to bathe in the
misorganized half-documentation, see e. g.
http://marc.theaimsgroup.com/?l=python-listm=111303919606261w=2
especially the reply that (as I read it) suggested reverse
engineering as a viable alternative to documentation.
As I read the reply, it was a smart-arse attempt at humour, a *PUN* on
the word list (mailing list versus Python list). What I would call
introspection (not reverse engineering) was then suggested.
Moreover, both of the concepts mentioned in the quoted thread
(sequence.index() and the in operator) are IMESHO adequately
documented.
Do you have any examples of what you regard as misorganized
half-documentation?
Description of classes:
* What's with Programmer's Note, is the other paragraph of the
description aimed at salesmen?
* Why isn't there a link to a description of new-style classes
(presumably to the New-style Classes essay since, as
http://www.python.org/doc/newstyle.html says, NSC aren't
integrated into the standard documentation.
* Aren't class objects instances of a builtin type? What should
I read into class __main__.foo at 0x81c050c?
distutils:
* sections 10.26 through 10.45 are completely empty
* http://docs.python.org/dist/listing-packages.html:
when you say packages = ['foo'] in your setup script couldn't
be any more vague I guess. Does the statement belong in the
global scope?
* http://docs.python.org/dist/listing-packages.html:
Then you would put package_dir = {'': 'lib'} in your setup
script.: does that statement belong in the global scope, or
is it a keyword argument for setup(), which would mean that the
listing at http://docs.python.org/dist/module-distutils.core.html
cannot be trusted as complete?
lists: this is a matter of taste, but I find the split of list
description between http://docs.python.org/lib/typesseq.html and
http://docs.python.org/lib/typesseq-mutable.html (without pointers
from typesseq.html to typesseq-mutable.html where I would expect
them, such as mentioning append()) confusing.
The above applies to other mutable sequential types as well, of
course.
In general, various parts of the documentation often refer the
reader to other parts without using html anchors, what should be
concise, accurate, and complete description is a meandering essay
with vague formulations (see quotes from the distutils manual
above), etc.
There's also this thing with easy access to individual nodes:
I often miss being able to type something like
http://docs.python.org/os.path.expanduser and be redirected to
http://docs.python.org/lib/module-os.path.html#l2h-1731
Mebbe it's just me, but I've been trying python on and off for
several years now, and it's always been precisely its documentation
that has made me back out. I know I'll get to know the language
quite well some time, but it'll be through scars, and I'll have many
f*cks behind me.
Here's a puzzle for you: Where does this list appear? What's missing?
..., Mullender, Nagata, Ng, Oner, Oppelstrup, ...
Sorry, I don't have time for puzzles.
--
How many Vietnam vets does it take to screw in a light bulb?
You don't know, man. You don't KNOW.
Cause you weren't THERE. http://bash.org/?255991
--
http://mail.python.org/mailman/listinfo/python-list
Re: [perl-python] Python documentation moronicities (continued)
Roman Neuhauser wrote: Here's a puzzle for you: Where does this list appear? What's missing? ..., Mullender, Nagata, Ng, Oner, Oppelstrup, ... Sorry, I don't have time for puzzles. nor for contributing, it seems. otherwise, your name would be on that list. /F -- http://mail.python.org/mailman/listinfo/python-list
Re: unicode em space in regex
Thanks. Is it true that any unicode chars can also be used inside regex literally? e.g. re.search(ur'+',mystring,re.U) I tested this case and apparently i can. But is it true that any unicode char can be embedded in regex literally. (does this apply to the esoteric ones such as other non-printing chars and combining forms...) Related...: The official python doc: http://python.org/doc/2.4.1/lib/module-re.html says: Regular expression pattern strings may not contain null bytes, but can specify the null byte using the \number notation. What is meant by null bytes here? Unprintable chars?? and the \number is meant to be decimal? and in what encoding? Xah [EMAIL PROTECTED] http://xahlee.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: [perl-python] Python documentation moronicities (continued)
# [EMAIL PROTECTED] / 2005-04-17 14:59:50 +0200: Roman Neuhauser wrote: Here's a puzzle for you: Where does this list appear? What's missing? ..., Mullender, Nagata, Ng, Oner, Oppelstrup, ... Sorry, I don't have time for puzzles. nor for contributing, it seems. otherwise, your name would be on that list. Right. There's a finite number of hours in a day, and I chose to spend most of it on FreeBSD, and my name is on that operating system's contributor list. You're welcome to use the results of the work. But anyway, I was honestly asked about what I considered suboptimal in the python documentation, and I honestly answered. Does that bother you? -- How many Vietnam vets does it take to screw in a light bulb? You don't know, man. You don't KNOW. Cause you weren't THERE. http://bash.org/?255991 -- http://mail.python.org/mailman/listinfo/python-list
Re: module to parse pseudo natural language?
Question is - is there a module out there that will already handle this approach? Try the python nltk. I haven't done stuff with it so far, but I'd certainly give it a try when I need natural language support. http://nltk.sourceforge.net/ -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Re: unicode em space in regex
Xah Lee wrote: Regular expression pattern strings may not contain null bytes, but can specify the null byte using the \number notation. What is meant by null bytes here? Unprintable chars?? and the \number is meant to be decimal? and in what encoding? The null byte is a byte with the integer value 0. Difficult, isn't it. The \number notation is, as you could read in http://docs.python.org/ref/strings.html, octal. Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: unicode em space in regex
Xah Lee wrote: Regular expression pattern strings may not contain null bytes, but can specify the null byte using the \number notation. What is meant by null bytes here? Unprintable chars?? no, null bytes. \0. \x00. ord(byte) == 0. chr(0). and the \number is meant to be decimal? octal. this is explained on the Regular Expression Syntax page. and in what encoding? null byte encoding? you're confused. /F -- http://mail.python.org/mailman/listinfo/python-list
ANN: Veusz 0.5 - a scientific plotting package
Veusz 0.5 - Velvet Ember Under Sky Zenith - http://home.gna.org/veusz/ Veusz is Copyright (C) 2003-2005 Jeremy Sanders [EMAIL PROTECTED] Licenced under the GPL (version 2 or greater) Veusz is a scientific plotting package written in Python (currently 100% Python). It uses PyQt for display and user-interfaces, and numarray for handling the numeric data. Veusz is designed to produce publication-ready Postscript output. Veusz provides a GUI, command line and scripting interface (based on Python) to its plotting facilities. The plots are built using an object-based system to provide a consistent interface. Changes from 0.4: Installation: * distutils used to install the package. RPMS available. Plotting: * Different error bar styles (diamond, curve...) * Matched axes, with the same scale on each * Data can be linked from external files instead of embedded in document * Filled regions under/over functions or xy plots * Improved function clipping near edge of plot * Default values can be set for settings, which are remembered between sessions (e.g. blue points for xy3). * Rotated text labels * Improved fitting, giving results from chi2, etc.. UI: * Can move around widgets and delete them * Exception dump dialog to send bug reports * Improved import dialog help * Propagate settings between widgets * Window positions are saved between sessions Reading data: * Better error handling when reading data + Numerous bug fixes Features of package: * X-Y plots (with errorbars) * Stepped plots (for histograms) * Line plots * Function plots * Fitting functions to data * Stacked plots and arrays of plots * Plot keys * Plot labels * LaTeX-like formatting for text * EPS output * Simple data importing * Scripting interface * Save/Load plots To be done: * Contour plots * Images * UI improvements * Import filters (for qdp and other plotting packages, fits, csv) * Data manipulation * Python embedding interface (for embedding Veusz in other programs). [some of the external interface is complete] Requirements: Python (probably 2.3 or greater required) http://www.python.org/ Qt (free edition) http://www.trolltech.com/products/qt/ PyQt (SIP is required to be installed first) http://www.riverbankcomputing.co.uk/pyqt/ http://www.riverbankcomputing.co.uk/sip/ numarray http://www.stsci.edu/resources/software_hardware/numarray Microsoft Core Fonts (recommended) http://corefonts.sourceforge.net/ For documentation on using Veusz, see the Documents directory. The manual is in pdf, html and text format (generated from docbook). If you enjoy using Veusz, I would love to hear from you. Please join the mailing lists at https://gna.org/mail/?group=veusz to discuss new features or if you'd like to contribute code. The newest code can always be found in CVS. Cheers Jeremy -- http://mail.python.org/mailman/listinfo/python-list
Re: module to parse pseudo natural language?
Le Sun, 17 Apr 2005 13:38:09 +0200, Andrew E a écrit : Hi all I've written a python program that adds orders into our order routing simulation system. It works well, and has a syntax along these lines: ./neworder --instrument NOKIA --size 23 --price MARKET --repeats 20 etc However, I'd like to add a mode that will handle, say: ./neworder buy 23 NOKIA at MKT x 20 I could enter several orders either by running multiple times, or use a comma-separated approach, like: ./neworder buy 23 NOKIA at MKT on helsinki, sell 20 NOKIA at market on helsinki It would be simpler to have the rule : one line == one order, action, command wahtever. The thing about this is that its a tolerant parser, so all of these should also work: # omit words like at, on ./neworder buy 23 NOKIA mkt helsinki # take any symbol for helsinki ./neworder buy 23 mkt helsinki # figure out that market=helsinki ./neworder buy 23 NOKIA at market price You have some variation of the same « buy » order. If you want to detail the semantics : you arrive to determine the different parameter of a BuyCommand : what, where, how (many) ... This semantic is expressed differently in english, US-english, french ... If you base your parser on regex you see that the same BuyOrder is represented by a number of variant : Please, buy 23 NOKIA at market Helsinki Acheter 40 actions Bouygues à la Bouse de Paris So you have for a given environment (orders management module) a number of commands expressed in pseudo-natural languages. Each command has a certain number of attributes name, module_name, parameters, variants(list of regexps for instance), description, short description, sample sentence (to be presented to the user in an interactive session if requested). An important attribute is naturally the action taken when the parser/interpreter matches the current line. So you group the description of the Commands in an easy to parse file and write an interpreter which on startup read such a file for the Commands it understands : command to load a module, to list the commands in the currently loaded module or in the interpreter, command to display the sample, short or long description (help about cmd or how to spell cmd)., command to stop the interpreter (and the program) ... command to read/include a file containings commands to parse and execute. Python is dynamic, with setattr() you can easily construct a Command object from its description. Here is what could be the description of a command to compute the equilibrium position in a stability module (using a «here» shell like syntax ): command equilibre eoc description eod La commande « equilibre » permet de lancer le calcul de la position d'équilibre du flotteur couramment décrit. position equilibre en partant de pqr 0.0/0.0/1.0 et h=8.500 les mots-clés sont equilibre pqr et h[=] eod sample eos equilibre pqr 0.0/0.0/1.0 avec h=8.500 eos # name of function to call action compute_equi # parameters of the command (a dictionary of parameters could be in # action's arguments parameters eop pqr h eop # The regexpes variants eov # the following regexp is with re.I (ignore case flag) : variant I eovi equilibrer?\spqr\s+(?Ppqr\d*\.\d*/\d*\.\d*/\d*\.\d*)\s+(?Ph\d*\.\d*) eovvi # syntax of regexp untested :-) variant eovi equilibrium\spqr\s+(?Ppqr\d*\.\d*/\d*\.\d*/\d*\.\d*)\s+(?Ph\d*\.\d*) eovvi eov eoc Thanks for any suggestions :) Andrew -- http://mail.python.org/mailman/listinfo/python-list
re module methods: flags(), pattern()
Python re module has methods flags and pattern. How to use these exactly? e.g. i tried print patternObj.flags() and the error is some int object is not callable. newpattern=re.compile(ur'\w+',patternObj.flags()) also bad. similar error for patternObj.pattern(). (and i suppose the same for groupindex() ) thanks. Xah [EMAIL PROTECTED] http://xahlee.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2.4 killing commercial Windows Python development ?
Terry Reedy writes: To put it another way, needing a Python interpreter to run .py files is no different from, for instance, needing a movie player to run .mpg files, and all Windows users are or need to become familiar with that general concept. The problem for windows users isn't that they have to download a movie player to play .mpg files... it's that they also have to download and install python/java runtime to play the player because it was written in python/java. Most won't bother and will download/install native win32 app instead. -- http://mail.python.org/mailman/listinfo/python-list
sscanf needed
Hi, I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. Is there a shorter way than using regular expressions? Is there a sscanf function as in C? Thanks, Uwe -- http://mail.python.org/mailman/listinfo/python-list
Re: sscanf needed
Uwe Mayer wrote: I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. import time help(time.strptime) Help on built-in function strptime in module time: strptime(...) strptime(string, format) - struct_time Parse a string to a time tuple according to a format specification. See the library reference manual for formatting codes (same as strftime()). /F -- http://mail.python.org/mailman/listinfo/python-list
Re: sscanf needed
Uwe Mayer skrev: Hi, I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. Look up time.strptime, it does exactly what you want. -- Leif Biberg Kristensen http://solumslekt.org/ -- http://mail.python.org/mailman/listinfo/python-list
How to compile ScientificPython-2.4.9 under XP cygwin environment?
I try to compile ScientificPython-2.4.9 (http://starship.python.net/~hinsen/ScientificPython/) under Windows XP cygwin environment using python 2.3.3 ,and gcc (GCC) 3.3.3 (cygwin special). The information shows as follows: -- Using netCDF installation in /usr/local running build running build_py running build_ext building 'Scientific_netcdf' extension gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o -L/usr/local/lib -L/usr/lib/python2.3/config -lnetcdf -lpython2.3 -o build/lib.cygwin-1.5.10-i686-2.3/Scientific/cygwin/Scientific_netcdf.dll build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o(.text+0x6eb): In function `initScientific_netcdf': /cygdrive/c/pygmt/ScientificPython-2.4.9/Src/Scientific_netcdf.c:2050: undefined reference to `_ncopts' build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o(.text+0x3067): In function `netcdf_seterror': /cygdrive/c/pygmt/ScientificPython-2.4.9/Src/Scientific_netcdf.c:46: undefined reference to `_ncerr' collect2: ld returned 1 exit status error: command 'gcc' failed with exit status 1 Does anyone meet same problem? -- http://mail.python.org/mailman/listinfo/python-list
Re: sscanf needed
Uwe Mayer wrote: Hi, I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. Something like this (adjust the format to suit): import datetime, time dt = datetime.datetime(*time.strptime(data, %Y-%m-%d %H:%M:%S)[:6]) Kent -- http://mail.python.org/mailman/listinfo/python-list
Re: sscanf needed
Uwe Mayer wrote: Hi, I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. Is there a shorter way than using regular expressions? Is there a sscanf function as in C? in addition to the other comments... I like re, because it gives me the most control. See below. import re import datetime class Converter: def __init__( self ): self.isoPattern = re.compile( (\d\d\d\d)-(\d\d)-(\d\d)[tT ](\d\d):(\d\d):(\d\d) ) def iso2date( self, isoDateString ): match = self.isoPattern.match( isoDateString ) if not match: raise ValueError( Not in ISO format: '%s' % isoDateString ) return datetime.datetime( int(match.group(1)), int(match.group(2)), int(match.group(3)), int(match.group(4)), int(match.group(5)), int(match.group(6)) ) c = Converter() def demo( iso ): try: date = c.iso2date( iso ) print Input '%s' - datetime: %s % ( iso, date ) except ValueError, e: print str(e) demo( 2005-04-21T12:34:56 ) demo( 2005-04-21 12:34:57 ) demo( 2005-04-2 12:34:57 ) -- http://mail.python.org/mailman/listinfo/python-list
How to compile ScientificPython-2.4.9 under XP cygwin environment?
Dear All, I try to compile ScientificPython-2.4.9 (http://starship.python.net/~hinsen/ScientificPython/) under Windows XP cygwin environment using python 2.3.3 ,and gcc (GCC) 3.3.3 (cygwin special). The information shows as fillows: -- Using netCDF installation in /usr/local running build running build_py running build_ext building 'Scientific_netcdf' extension gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o -L/usr/local/lib -L/usr/lib/python2.3/config -lnetcdf -lpython2.3 -o build/lib.cygwin-1.5.10-i686-2.3/Scientific/cygwin/Scientific_netcdf.dll build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o(.text+0x6eb): In function `initScientific_netcdf': /cygdrive/c/pygmt/ScientificPython-2.4.9/Src/Scientific_netcdf.c:2050: undefined reference to `_ncopts' build/temp.cygwin-1.5.10-i686-2.3/Src/Scientific_netcdf.o(.text+0x3067): In function `netcdf_seterror': /cygdrive/c/pygmt/ScientificPython-2.4.9/Src/Scientific_netcdf.c:46: undefined reference to `_ncerr' collect2: ld returned 1 exit status error: command 'gcc' failed with exit status 1 Does anyone meet same problem? -- Zhuanshi He / Z. He Advanced Environmental Monitoring Research Center (ADEMRC) Gwangju Institute of Science and Technology (GIST) 1 Oryong-dong, Puk-gu, Gwangju 500-712, South Korea Tel: +82-(0)62-970-3406 Fax: +82-(0)62-970-3404 -- http://mail.python.org/mailman/listinfo/python-list
Re: re module methods: flags(), pattern()
Xah Lee wrote: Python re module has methods flags and pattern. How to use these exactly? e.g. i tried print patternObj.flags() and the error is some int object is not callable. Where do you read methods? Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: module to parse pseudo natural language?
Andrew E [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Hi all I've written a python program that adds orders into our order routing simulation system. It works well, and has a syntax along these lines: ./neworder --instrument NOKIA --size 23 --price MARKET --repeats 20 etc However, I'd like to add a mode that will handle, say: ./neworder buy 23 NOKIA at MKT x 20 I could enter several orders either by running multiple times, or use a comma-separated approach, like: ./neworder buy 23 NOKIA at MKT on helsinki, sell 20 NOKIA at market on helsinki The thing about this is that its a tolerant parser, so all of these should also work: # omit words like at, on ./neworder buy 23 NOKIA mkt helsinki # take any symbol for helsinki ./neworder buy 23 mkt helsinki # figure out that market=helsinki ./neworder buy 23 NOKIA at market price I've started writing a simple state-based parser, usage like: class NaturalLanguageInsructionBuilder: def parse( self, arglist ): Given a sequence of args, return an Instruction object ... return Instruction( instrument, size, price, ... ) class Instruction: encapsulate a single instruction to buy, sell, etc def __init__( self, instrument, size, price, ... ): ... This doesn't work yet, but I know with time I'll get there. Question is - is there a module out there that will already handle this approach? Thanks for any suggestions :) There's NLTK (on Sourceforge) which has already been mentioned. However, it's a teaching tool, not a real production natural language parser. I'd suggest you step back from the problem and take a wider view. Parsing natural language, in all its variations, is an unsolved research problem that is part of what has given Artificial Intelligence somewhat of a black eye. Your problem is, however, much simpler than the general one: you've got a limited number of commands which pretty much all follow the VO (verb operands) pattern. You've also got a lot of words from limited and disjunct vocabularies that can be used to drive the parse. In your example, at least one of 'buy' and 'sell' is required to start a clause, MKT is one of maybe a half dozen qualifiers that specify other information that must be present, there are a limited number of exchanges, and the number of shares seems to be the only number present. I'd also take a bit of advice from the XP community: don't write the library first, wait until you've got at least three working examples so you know the services that the library really needs to support. John Roth Andrew -- http://mail.python.org/mailman/listinfo/python-list
Re: pydoc preference for triple double over triple single quotes -- anyreason?
Kent Johnson said unto the world upon 2005-04-16 16:41: Brian van den Broek wrote: Hi all, I'm posting partly so my problem and solution might be more easily found by google, and partly out of mere curiosity. I've just spent a frustrating bit of time figuring out why pydoc didn't extract a description from my module docstrings. Even though I had a well formed docstring (one line, followed by a blank line, followed by the rest of the docstring), when I ran Module docs, my modules showed up as having no description. (Module docs referring to the shortcut installed on Windows that launches the pydoc server.) ?? It works for me with triple-single quoted strings...from a quick look it appears that pydoc uses inspect which looks at the __doc__ attribute; do your modules have __doc__ attributes? Kent Thanks for the reply, Kent. (Also to Thomas in another reply addressed below.) Kent, that's odd. My module does have a valid docstring and hence a __doc__ attribute (I did explicitly check). help(my_module) works fine at the prompt. It is just the results list in the TKinter interface to the pydoc server application that doesn't seem to pick up my module's description (in the first line of its docstring) when the docstring is triple-single quoted. Either way, it's no big deal; my post was at least as much to have a googleable record of the situation as to figure out why. That said, it still does puzzle me that the pydoc server treats the two styles of triple quoted docstrings differently on my system (Python 2.4.1, Windows Me). Thomas suggested the preference might be related to Emacs behaviour--that is something I know little about :-) He also suggested that it could be that pydoc is following the PEP 257 http://www.python.org/peps/pep-0257.html recommendation to use triple-double quoting. That might be, but if that's the explanation, it just pushes the puzzle up a level for me :-) Anyway, thanks again to both, Brian vdB -- http://mail.python.org/mailman/listinfo/python-list
Re: unicode em space in regex
Xah Lee wrote: Thanks. Is it true that any unicode chars can also be used inside regex literally? e.g. re.search(ur'+',mystring,re.U) I tested this case and apparently i can. Yes. In fact, when you write u\u2003 or u doesn't matter to re.search. Either way you get a Unicode object with U+2003 in it, which is processed by SRE. But is it true that any unicode char can be embedded in regex literally. (does this apply to the esoteric ones such as other non-printing chars and combining forms...) Yes. To SRE, only the Unicode ordinal values matter. To determine whether something matches, it needs to have the same ordinal value in the string that you have in the expression. No interpretation of the character is performed, except for the few characters that have markup meaning in regular expressions (e.g. $, \, [, etc) Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Problem with unpack hex to decimal
Hello,
I was looking at this:
http://docs.python.org/lib/module-struct.html
and tried the following
import struct
struct.calcsize('h')
2
struct.calcsize('b')
1
struct.calcsize('bh')
4
I would have expected
struct.calcsize('bh')
3
what am I missing ?
Thanks in advance,
Jake.
--
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Re: Problem with unpack hex to decimal
[EMAIL PROTECTED] wrote:
I was looking at this:
http://docs.python.org/lib/module-struct.html
and tried the following
import struct
struct.calcsize('h')
2
struct.calcsize('b')
1
struct.calcsize('bh')
4
I would have expected
struct.calcsize('bh')
3
what am I missing ?
the sentence
By default, C numbers are represented in the machine's native format
and byte order, and properly aligned by skipping pad bytes if necessary
(according to the rules used by the C compiler).
and the text and table following that sentence.
/F
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Re: whitespace , comment stripper, and EOL converter
I found the bug and hope I have squashed it. Single and qouble quoted strings that were assignments and spanned multilines using \ , were chopped after the first line. example: __date__ = 'Apr 16, 2005,' \ 'Jan 15 2005,' \ 'Oct 24 2004' became: __date__ = 'Apr 16, 2005,' \ Not good :( tokenizer sends this as: name operator string string string newline I added test for string assignments that end in \. A flag is set and then all strings till a newline are ignored. Also rearranged the script a little. Maybe that will do it ... Updates available at The script is located at: http://bellsouthpwp.net/m/e/mefjr75/python/stripper.py M.E.Farmer -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with unpack hex to decimal
[EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hello,
I was looking at this:
http://docs.python.org/lib/module-struct.html
and tried the following
import struct
struct.calcsize('h')
2
struct.calcsize('b')
1
struct.calcsize('bh')
4
I would have expected
struct.calcsize('bh')
3
what am I missing ?
Not sure, however I also find the following confusing:
struct.calcsize('hb')
3
struct.calcsize('hb') == struct.calcsize('bh')
False
I could understand aligning to multiples of 4, but why is 'hb' different
from 'bh'?
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Re: Decorator Syntax For Recursive Properties
Jeffrey Froman wrote: it is the originating node (the node trying to find its ancestors). So something like this didn't work for me: @property def ancestors(self): if self.parent is None: return [self.name] return [self.name] + self.parent.ancestors But this will, I suppose: @property def ancestors(self): if self.parent: return self.parent.ancestors + [self.parent] return [] A non-recursive variant: @property def ancestors(self): result = [] node = self.parent while node: result.append(node) node = node.parent result.reverse() return result Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
On 17 Apr 2005 01:46:14 -0700, Kay Schluehr [EMAIL PROTECTED] wrote: Ron_Adam wrote: I sort of wonder if this is one of those things that looks like it could be useful at first, but it turns out that using functions and class's in the proper way, is also the best way. (?) I think Your block is more low level. Yes, that's my thinking too. I'm sort of looking to see if there is a basic building blocks here that can be used in different situations but in very consistent ways. And questioning the use of it as well. It is like copying and pasting code-fragments together but in reversed direction: ... Yes, in a function call, you send values to a remote code block and receive back a value. The reverse is to get a remote code block, then use it. In this case the inserted code blocks variables become local, So my point is you don't need to use arguments to pass values. But you do need to be very consistent in how you use the code block. (I'm not suggesting we do this BTW) The advantage to argument passing in this case would be that it puts a control on the block that certain arguments get assigned before it gets executed. Is it possible to have a tuple argument translation independently of a function call? This would also be a somewhat lower level operation, but might be useful, for example at a certain point in a program you want to facilitate that certain values are set, you could use a tuple argument parser to do so. It could act the same way as a function call argument parser but could be used in more places and it would raise an error as expected. Basically it would be the same as: def argset(x,y,z=1): return x,y,z But done in a inline way. a,b,c = (x,y,z=1) # looks familiar doesn't it. ;-) As an inline expression it could use '%' like the string methods, something like this? (x,y,z=1)%a,b,c # point x,y,z to a,b,c (?) And combined with code chunks like this. def chunk: # code chunk, ie.. no arguments. # set (x,y) # informal arguments commented return x+y # return a value for inline use value = (x,y)%a,b: chunk# use local code chunk as body I think this might resemble some of the suggested lambda replacements. The altenative might be just to have functions name space imported as an option. def f(x,y): return x+y z = dolocal f(1,2) #But why would I want to do this? I think these pre-peps are really about doing more with less typing and don't really add anything to Python. I also feel that the additional abstraction when used only to compress code, will just make programs harder to understand. You have to change all the environments that use the thunk e.g. renaming variables. It is the opposite direction of creating abstractions i.e. a method to deabstract functions: introduce less modularity and more direct dependencies. This is the reason why those macros are harmfull and should be abandoned from high level languages ( using them in C is reasonable because code expansion can be time efficient and it is also a way to deal with parametric polymorphism but Python won't benefit from either of this issues ). Ciao, Kay I agree. If a code block of this type is used it should be limited to within the function it's defined in. The advantage, if it's used in a bare bones low level way with no argument passing, would be some performance benefits over function calls in certain situations. That is, a small reusable code block without the function call overhead. But only use it in the local name space it's defined in. Otherwise use a function or a class. Cheers, Ron -- http://mail.python.org/mailman/listinfo/python-list
Re: Accessing multidimensional lists with an index list
Gabriel Birke wrote:
Given the multidimensional list l:
l = [ {'v1': 1, 'v2': 2},
[ {'v1':4, 'v2': 7},
{'v1': 9, 'v2': 86},
[ {'v1': 77, 'v2': 88}]
]
]
I want to access specific items the indices of which are stored in
another list. For now, I created a function to do this:
def getNestedValue(l, indices):
while len(indices) 0:
i = indices.pop(0)
l = l[i] #In future versions, put error checking here
return l
Is there a more elegant or performant language construct to accomplish
my task?
def getNestedValue(l, indices):
for i in indices:
l = l[i] #In future versions, put error checking here
return l
Kent
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Re: pysvn install on freebsd
On 2005-04-17, Timothy Smith [EMAIL PROTECTED] wrote: has anyone used or installed this on fbsd the install for it is totally redundant. i get this error for it make -f freebsd.mak clean all test cd ../Source make -f pysvn_freebsd_py.mak clean make: cannot open pysvn_freebsd_py.mak. *** Error code 2 Stop in /usr/home/timothy/pysvn-1.1.2/Extension/Builder. Have you tried /usr/ports/devel/subversion-python/ ? -- http://mail.python.org/mailman/listinfo/python-list
Re: sscanf needed
On 2005-04-17, Andrew E [EMAIL PROTECTED] wrote: Uwe Mayer wrote: Hi, I've got a ISO 8601 formatted date-time string which I need to read into a datetime object. Is there a shorter way than using regular expressions? Is there a sscanf function as in C? in addition to the other comments... I like re, because it gives me the most control. See below. import re import datetime class Converter: def __init__( self ): self.isoPattern = re.compile( (\d\d\d\d)-(\d\d)-(\d\d)[tT ](\d\d):(\d\d):(\d\d) ) def iso2date( self, isoDateString ): match = self.isoPattern.match( isoDateString ) if not match: raise ValueError( Not in ISO format: '%s' % isoDateString ) return datetime.datetime( int(match.group(1)), int(match.group(2)), int(match.group(3)), int(match.group(4)), int(match.group(5)), int(match.group(6)) ) c = Converter() def demo( iso ): try: date = c.iso2date( iso ) print Input '%s' - datetime: %s % ( iso, date ) except ValueError, e: print str(e) demo( 2005-04-21T12:34:56 ) demo( 2005-04-21 12:34:57 ) demo( 2005-04-2 12:34:57 ) That's nice. We should get some code in to the module so that it is simple to round-trip the default datetime timestamps. -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with unpack hex to decimal
Jonathan Brady wrote:
... I also find the following confusing:
struct.calcsize('hb')
3
struct.calcsize('hb') == struct.calcsize('bh')
False
I could understand aligning to multiples of 4, but why is 'hb' different
from 'bh'?
Pad bytes have never been, as far as I know, added
at the end of structs in C, only between fields, when
required. So the leading b gets a following pad
byte, but the trailing one doesn't need padding.
-Peter
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Re: re module methods: flags(), pattern()
Xah Lee wrote: Python re module has methods flags and pattern. How to use these exactly? From the Python 2.3 documentation, section 2.4.2 flags The flags argument used when the RE object was compiled, or 0 if no flags were provided. groupindex A dictionary mapping any symbolic group names defined by (?Pid) to group numbers. The dictionary is empty if no symbolic groups were used in the pattern. pattern The pattern string from which the RE object was compiled. Comments derived from the docs and error messages: e.g. i tried print patternObj.flags() and the error is some int object is not callable. = flags is an int object newpattern=re.compile(ur'\w+',patternObj.flags()) also bad. = flags is still an int object similar error for patternObj.pattern(). = pattern is a string (and i suppose the same for groupindex() ) = groupindex is a dict thanks. Xah [EMAIL PROTECTED] http://xahlee.org/ The documentation is not that bad that one should not read it at all ;) If You wrestle with regexps I can recommend an old but still usefull little wrapper I found eventually on the Vaults of Parnassus which is called reverb.py Ciao, Kay -- http://mail.python.org/mailman/listinfo/python-list
Re: pydoc preference for triple double over triple single quotes-- anyreason?
Kent Johnson said unto the world upon 2005-04-17 16:17: Brian van den Broek wrote: Kent Johnson said unto the world upon 2005-04-16 16:41: Brian van den Broek wrote: I've just spent a frustrating bit of time figuring out why pydoc didn't extract a description from my module docstrings. Even though I had a well formed docstring (one line, followed by a blank line, followed by the rest of the docstring), when I ran Module docs, my modules showed up as having no description. (Module docs referring to the shortcut installed on Windows that launches the pydoc server.) ?? It works for me with triple-single quoted strings...from a quick look it appears that pydoc uses inspect which looks at the __doc__ attribute; do your modules have __doc__ attributes? Kent, that's odd. My module does have a valid docstring and hence a __doc__ attribute (I did explicitly check). help(my_module) works fine at the prompt. It is just the results list in the TKinter interface to the pydoc server application that doesn't seem to pick up my module's description (in the first line of its docstring) when the docstring is triple-single quoted. I'm not sure what you mean by the results list in the TKinter interface to the pydoc server. I ran the server, clicked open browser and browsed to a module in site-packages; that worked fine for me under Win2K and Python 2.4.1. Kent By the TKinter interface to the pydoc server I mean the window that pops up when you select the Module Docs shortcut. It is pictured here http://www.onlamp.com/python/2001/04/18/graphics/pydoc1.gif, which is Fig.1 in an article on pydoc by Cameron Laird http://www.onlamp.com/pub/a/python/2001/04/18/pydoc.html. By results list I mean the gray-backround'ed box immediately below the Search for input box in the illustration. The puzzle for me was that if I enter my module name in the Search for box, it shows up in the list of results, as expected. But whether the results list entry for my module incorporates the description form my module's docstring or instead shows my module as having (no description) is a function of which style of triple quotes I used. (If my module docstring is enclosed by triple double quotes, the description is extracted from my module's docstring. If it uses triple single quotes instead, for purposes of the results list my module's docstring is ignored, and the module is listed as having (no description).) At any rate, such was the (minor) irritation which caused me to launch the thread. It took me a bit to work out that the quote-style was what made the difference, and a preliminary google didn't cast light. 2/3rd's the point of the post was to make the problem resolvable by google. Thanks for your continued efforts to understand what I'm on about. :-) Best to all, Brian vdB -- http://mail.python.org/mailman/listinfo/python-list
Re: distutils question: different projects under same namespace
Le 16 Apr 2005 01:20:34 -0700, Qiangning Hong a écrit :
To avoid namespace confliction with other Python packages, I want all
my projects to be put into a specific namespace, e.g. 'hongqn' package,
so that I can use from hongqn.proj1 import module1, from
hongqn.proj2.subpack1 import module2, etc.
That makes sense
These projects are developed and maintained and distributed seperately,
so I should not make a whole 'hongqn' package with one setup.py. I
must write setup.py scripts for each project. I meet a problem here.
For instance, I am writing setup.py script for proj1. I use the
following parameters when calling distutils.core.setup:
setup(
...
package_dir = {'hongqn.proj1': 'proj1'},
packages = ['hongqn.proj1'],
...
)
python setup.py install will create /usr/lib/python2.3/hongqn/proj1
directory and copy proj1/*.py there. But this is UNUSABLE! There is
NO __init__.py file under /usr/lib/python2.3/hongqn/ so that import
hongqn.proj1 will fail!
You can detect if there is __init__.py in the hongqn directory.
I am considering manually create this __init__.py by hacking the
install_lib command. But before making my hands dirty, I want to know
if there is an official solution exists or others have already
success stories on this matter.
It seems that this problem is tackled in the logilab packages : for
example, you install first the logilab common libraries and then pylint.
So the problem is to define the dependencies of your projects and hence
the order of installation.
As a note, I wish the solution can handle setup.py bdist and
bdist_wininst well.
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Re: pre-PEP: Suite-Based Keywords
Oren Tirosh wrote: Take a look at Nick Coglan's with proposal: http://groups.google.co.uk/groups?selm=mailman.403.1105274631.22381.python-list%40python.org It addresses many of the same issues (e.g. easy definition of properties). It is more general, though: while your proposal only applies to keyword arguments in a function call this one can be used to name any part of a complex expression and define it in a suite. I think that a good hybrid solution would be to combine the with block with optional use of the ellipsis to mean all names defined in the with block. See also the thread resulting from Andrey Tatarinov's original proposal (using the keyword where): http://groups.google.co.uk/groups?selm=3480qqF46jprlU1%40individual.net Thanks for the links. I wasn't aware of that proposal. I agree that a hybrid solution is probably the way to go. Does anyone know if the 'where' keyword is only for readability (or does it disambiguate the syntax in some situations)? I think I prefer leaving it off. Maybe using '**' would be better than '...' since it already is used to indicate keyword arguments. Example: class C(object): x = property(**): doc = I'm the 'x' property. def fget(self): return self.__x def fset(self, value): self.__x = value def fdel(self): del self.__x -Brian -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with unpack hex to decimal
On Sun, 17 Apr 2005 20:47:20 +0100, Jonathan Brady
[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hello,
I was looking at this:
http://docs.python.org/lib/module-struct.html
and tried the following
import struct
struct.calcsize('h')
2
struct.calcsize('b')
1
struct.calcsize('bh')
4
I would have expected
struct.calcsize('bh')
3
what am I missing ?
A note for the original poster: unpack hex to decimal (the subject
line from your posting) is an interesting concept. Hex[adecimal] and
decimal are ways of representing the *same* number.
Let's take an example of a two-byte piece of data. Suppose the first
byte has all bits set (== 1) and the second byte has all bits clear
(== 0). The first byte's value is hexadecimal FF or decimal 255,
whether or not you unpack it, if you are interpreting it as an
unsigned number ('B' format). Signed ('b' format) gives you
hexadecimal -1 and decimal -1. The second byte's value is 0
hexadecimal and 0 decimal however you interpret it.
Suppose you want to interpret the two bytes as together representing a
16-bit signed number (the 'h' format). If the perp is little-endian,
the result is hex FF and decimal 255; otherwise it's hex -100 and
decimal -256.
Not sure, however I also find the following confusing:
struct.calcsize('hb')
3
struct.calcsize('hb') == struct.calcsize('bh')
False
I could understand aligning to multiples of 4,
Given we know nothing about the OP's platform or your platform, 4 is
no more understandable than any other number.
but why is 'hb' different
from 'bh'?
Likely explanation: the C compiler aligns n-byte items on an n-byte
boundary. Thus in 'hb', the h is at offset 0, and the b can start OK
at offset 2, for a total size of 3. With 'bh', the b is at offset 0,
but the h can't (under the compiler's rules) start at 1, it must start
at 2, for a total size of 4.
Typically, you would use native byte ordering and alignment (the
default) only where you are accessing data in a C struct that is in
code that is compiled on your platform [1]. When you are picking apart
a file that has been written elsewhere, you will typically need to
read the documentation for the file format and/or use trial error to
determine which prefix (@, , ) you should use. If I had to guess for
you, I'd go for .
[1] Care may need to be taken if the struct is defined in source
compiled by a compiler *other* than the one used to compile your
Python executable -- there's a slight chance you might need to fiddle
with the foreign compiler's alignment options to make it suit.
HTH,
John
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Re: Decorator Syntax For Recursive Properties
Peter Otten wrote: something like this didn't work for me: snip But this will, I suppose: @property def ancestors(self): if self.parent: return self.parent.ancestors + [self.parent] return [] A non-recursive variant: @property def ancestors(self): result = [] node = self.parent while node: result.append(node) node = node.parent result.reverse() return result Indeed, both of these patterns suit my needs. Thanks very much for the eye-opening insights. Jeffrey -- http://mail.python.org/mailman/listinfo/python-list
Re: module to parse pseudo natural language?
Andrew E wrote: Hi all I've written a python program that adds orders into our order routing simulation system. It works well, and has a syntax along these lines: ./neworder --instrument NOKIA --size 23 --price MARKET --repeats 20 etc However, I'd like to add a mode that will handle, say: ./neworder buy 23 NOKIA at MKT x 20 I could enter several orders either by running multiple times, or use a comma-separated approach, like: ./neworder buy 23 NOKIA at MKT on helsinki, sell 20 NOKIA at market on helsinki You could add a string option instead: $ neworder -c 'buy 23 NOKIA at MKT on helsinki, sell 20 NOKIA at market on helsinki' This would leave your current option parsing in tact. Then just split on the comma. Another suggestion would be to drop into an interactive mode if no arguments are passed: $ neworder -? buy 23 NOKIA at MKT on helsinki -? sell 20 NOKIA at market on helsinki -? ^d The thing about this is that its a tolerant parser, so all of these should also work: # omit words like at, on ./neworder buy 23 NOKIA mkt helsinki # take any symbol for helsinki ./neworder buy 23 mkt helsinki # figure out that market=helsinki ./neworder buy 23 NOKIA at market price I've started writing a simple state-based parser, usage like: class NaturalLanguageInsructionBuilder: def parse( self, arglist ): Given a sequence of args, return an Instruction object ... return Instruction( instrument, size, price, ... ) class Instruction: encapsulate a single instruction to buy, sell, etc def __init__( self, instrument, size, price, ... ): ... This doesn't work yet, but I know with time I'll get there. Question is - is there a module out there that will already handle this approach? Thanks for any suggestions :) Andrew If I were in your situation, I'd probably write a BNF for the tiny-language. This would help wrap my brain around the problem. The BNF would help show what kind of regular expression you are looking at creating as well. -- bytecolor -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
Ron_Adam wrote:
On Sat, 16 Apr 2005 17:25:00 -0700, Brian Sabbey
Yes, much of what thunks do can also be done by passing a function
argument. But thunks are different because they share the surrounding
function's namespace (which inner functions do not), and because they can
be defined in a more readable way.
Generally my reason for using a function is to group and separate code
from the current name space. I don't see that as a drawback.
I agree that one almost always wants separate namespaces when defining a
function, but the same is not true when considering only callback
functions. Thunks are a type of anonymous callback functions, and so a
separate namespace usually isn't required or desired.
Are thunks a way to group and reuse expressions in the current scope?
If so, why even use arguments? Wouldn't it be easier to just declare
what I need right before calling the group? Maybe just informally
declare the calling procedure in a comment.
def thunkit: # no argument list defines a local group.
# set thunk,x and y before calling.
before()
result = thunk(x,y)
after()
def foo(x,y):
x, y = y, x
return x,y
thunk = foo
x,y = 1,2
do thunkit
print result
- (2,1)
Since everything is in local name space, you really don't need to
pass arguments or return values.
I'm kicking myself for the first example I gave in my original post in
this thread because, looking at it again, I see now that it really gives
the wrong impression about what I want thunks to be in python. The
'thunkit' function above shouldn't be in the same namespace as the thunk.
It is supposed to be a re-usable function, for example, to acquire and
release a resource. On the other hand, the 'foo' function is supposed to
be in the namespace of the surrounding code; it's not re-usable. So your
example above is pretty much the opposite of what I was trying to get
across.
The 'do' keyword says to evaluate the group. Sort of like eval() or
exec would, but in a much more controlled way. And the group as a
whole can be passed around by not using the 'do'. But then it starts
to look and act like a class with limits on it. But maybe a good
replacement for lambas?
I sort of wonder if this is one of those things that looks like it
could be useful at first, but it turns out that using functions and
class's in the proper way, is also the best way. (?)
I don't think so. My pickled_file example below can't be done as cleanly
with a class. If I were to want to ensure the closing of the pickled
file, the required try/finally could not be encapsulated in a class or
function.
You're right that, in this case, it would be better to just write
f(stuff, 27, 28). That example was just an attempt at describing the
syntax and semantics rather than to provide any sort of motivation. If
the thunk contained anything more than a call to 'stuff', though, it would
not be as easy as passing 'stuff' to 'f'. For example,
do f(27, 28):
print stuff()
would require one to define and pass a callback function to 'f'. To me,
'do' should be used in any situation in which a callback *could* be used,
but rarely is because doing so would be awkward. Probably the simplest
real-world example is opening and closing a file. Rarely will you see
code like this:
def with_file(callback, filename):
f = open(filename)
callback(f)
f.close()
def print_file(file):
print file.read()
with_file(print_file, 'file.txt')
For obvious reasons, it usually appears like this:
f = open('file.txt')
print f.read()
f.close()
Normally, though, one wants to do a lot more than just print the file.
There may be many lines between 'open' and 'close'. In this case, it is
easy to introduce a bug, such as returning before calling 'close', or
re-binding 'f' to a different file (the former bug is avoidable by using
'try'/'finally', but the latter is not). It would be nice to be able to
avoid these types of bugs by abstracting open/close. Thunks allow you to
make this abstraction in a way that is more concise and more readable than
the callback example given above:
How would abstracting open/close help reduce bugs?
I gave two examples of bugs that one can encounter when using open/close.
Personally, I have run into the first one at least once.
I'm really used to using function calls, so anything that does things
differently tend to be less readable to me. But this is my own
preference. What is most readable to people tends to be what they use
most. IMHO
do f in with_file('file.txt'):
print f.read()
Thunks are also more useful than callbacks in many cases since they allow
variables to be rebound:
t = no file read yet
do f in with_file('file.txt'):
t = f.read()
Using a callback to do the above example is, in my opinion, more
difficult:
def with_file(callback, filename):
f = open(filename)
t = callback(f)
f.close()
return t
def my_read(f):
return
Re: pre-PEP: Suite-Based Keywords
Brian Sabbey wrote: Does anyone know if the 'where' keyword is only for readability (or does it disambiguate the syntax in some situations)? I think I prefer leaving it off. To answer my own question, I see by reading the where threads that using the 'where' keyword allows things such as: # Design by contract (from Nick Coghlan) @dbc(pre, post) def foo(): pass with: def pre(): pass def post(): pass -- http://mail.python.org/mailman/listinfo/python-list
python.exe on Mac OS X!?
I did a source code build of Python 2.4.1 on OS X (10.3.8) and the executable produced was 'python.exe'. Can someone tell me whether this is a bug, feature, or UserError? % ./configure snip % make snip % ./python.exe Python 2.4.1 (#1, Apr 17 2005, 12:14:12) [GCC 3.3 20030304 (Apple Computer, Inc. build 1495)] on darwin -- http://mail.python.org/mailman/listinfo/python-list
Re: variables exist
In article [EMAIL PROTECTED],
[EMAIL PROTECTED] (fabian) wrote:
how testing if a variable exists in python as isset in php??
Would the following be a satisfactory implementation?
def isset(varname, lloc = locals()):
return varname in lloc or varname in globals()
I believe this works as desired:
x = 5
def f(y):
... z = 10
... print isset('z') ## == True
... print isset('y') ## == True
... print isset('x') ## == True
...
Tests:
f(1) ## As shown above
print isset('z') ## == False
print isset('y') ## == False
print isset('x') ## == True
print isset('varname') ## == False
print isset('lloc')## == False
lloc = foo!
print isset('lloc')## == True
Perhaps this is not the most elegant solution, but I believe it handles
scoping correctly.
-M
--
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http://www.dartmouth.edu/~sting/ | Dartmouth College, Hanover, NH, USA
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Finding name of running script
Is it a more pythonic way of finding the name of the running script than these? from os import sep from sys import argv print argv[0].split(sep)[-1] # or print locals()['__file__'].split(sep)[-1] # or print globals()['__file__'].split(sep)[-1] -- http://mail.python.org/mailman/listinfo/python-list
Re: MS SQL Server/ODBC package for Python
:) Knock away, as my info isn't scientific anyway. In my case, ASA is *not* local. The db is running on a 500MHz x 2 server with 768MB RAM, over 100BaseT connection. That same server is also running the MSSQL instance, and IIS. Running your benchmark, I ran into a couple of interesting points. Using mx.ODBC, my times were 0.54 seconds and 6.56 seconds respectively, while using adodbapi my results are 3.55 seconds and 25.9 seconds respectively. mx.ODBC is faster with the simple query you provide. Next I modified the benchmark to reflect my particular circumstances more accurately (?Maybe? Comments invited). I changed the query to one of the queries in regular use in my application. This query selects 26 columns from 3 joined tables, with a where clause where f476 = ?, and I provide the missing value as a tuple in the execute statement. Note that, as I mentioned in my reply to M-A, the f476 field is not indexed, and is a long varchar. Again, the system is bought, so I have no control over the schema. ;) The other change I made was to reduce the number of iterations from 100 to 10. Since there are 128000 records in the main table, the wait for 100 iterations was too long for my patience. Under these circumstances, mx.ODBC's numbers are 188.49 seconds and 377.56 seconds respectively, and adodbapi's times are 111.15 seconds and 223.55 seconds respectively. My first wall-clock impressions are obvious exaggerations of reality, for which I duly apologize to all. However, adodbapi did prove to be faster in my admittedly very wacky common use case. Slower to connect, but faster to run a substantial query. Comments? Questions? Suggestions for improvement? -- http://mail.python.org/mailman/listinfo/python-list
Re: MS SQL Server/ODBC package for Python
I switched around the order, both in the actual application and in my tests as replied to Francois Lepoutre above. Results were consistent, after the first run of any given test, which unsurprisingly took a bit longer. -- http://mail.python.org/mailman/listinfo/python-list
Re: python.exe on Mac OS X!?
Rodney Maxwell wrote: I did a source code build of Python 2.4.1 on OS X (10.3.8) and the executable produced was 'python.exe'. Can someone tell me whether this is a bug, feature, or UserError? I'm not sure. Why don't you grab the binary? http://www.python.org/ftp/python/2.4.1/MacPython-OSX-2.4.1-1.dmg -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
terminal shutdown
i wrote a script that accesses files at random from the locatedb database. it then prints a random line from the file it's accessed to the terminal screen. this runs continuously and at times makes the terminal behave strangely (chaning font colors, output writing over itself on the screen, etc) -- i like this strange behavior, but the behavior i don't like is when the terminal window closes on its own. i suspect that the script isn't crashing, but that characters are being displayed that interrupt terminal somehow. i'm on mas os x. any help on this would be greatly greatly appreicated. thanks, dan -- http://mail.python.org/mailman/listinfo/python-list
Re: Finding name of running script
print locals()['__file__'].split(sep)[-1] .split(sep)[-1] is pretty dense reading. try: print os.basename(locals()['__file__']) runes wrote: Is it a more pythonic way of finding the name of the running script than these? from os import sep from sys import argv print argv[0].split(sep)[-1] # or print locals()['__file__'].split(sep)[-1] # or print globals()['__file__'].split(sep)[-1] M.E.Farmer -- http://mail.python.org/mailman/listinfo/python-list
Re: python.exe on Mac OS X!?
Rodney I did a source code build of Python 2.4.1 on OS X (10.3.8) and Rodney the executable produced was 'python.exe'. Can someone tell me Rodney whether this is a bug, feature, or UserError? The default file system on MacOSX is case insensitive. As a result the .exe extension is required to disambiguate the generated executable from the Python directory in the source distro. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: Pattern Matching Given # of Characters and no String Input; use RegularExpressions?
tiissa [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED]...
tiissa wrote:
If you know the number of characters to match can't you just compare
slices?
If you don't, you can still do it by hand:
In [7]: def cmp(s1,s2):
: diff_map=[chr(s1[i]!=s2[i]) for i in range(min(len(s1),
len(s2)))]
: diff_index=''.join(diff_map).find(chr(True))
: if -1==diff_index:
: return min(len(s1), len(s2))
: else:
: return diff_index
:
In [8]: cmp('cccat','cccap')
Out[8]: 4
In [9]: cmp('ccc','cccap')
Out[9]: 3
In [10]: cmp('cccat','dddfa')
Out[10]: 0
I will look at that, although if i have 300 images i dont want to type
all the comparisons (In [9]: cmp('ccc','cccap')) by hand, it would
just be easier to sort them then :).
I got it somewhat close to working in visual basic:
If Left$(Cells(iRow, 1).Value, Count) = Left$(Cells(iRow - 1,
1).Value, Count) Then
What it says is when comparing a list, it looks at the 'Count' left
number of characters in the cell and compares it to the row cell
above's 'Count' left number of characters and then does the task (i.e.
makes a directory, moves the files) if they are equal.
I will look for a Left$(str) function that looks at the first X
characters for python :)).
Thank you for your help!
Synonymous
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Re: python.exe on Mac OS X!?
executable produced was 'python.exe'. Can someone tell me whether this is a bug, feature, or UserError? I'm not sure. Why don't you grab the binary? http://www.python.org/ftp/python/2.4.1/MacPython-OSX-2.4.1-1 .dmg Because I need to keep multiple versions of Python on this machine, and as far as I can tell the binary installer overwrites the default installed version. I could be wrong. -- http://mail.python.org/mailman/listinfo/python-list
Re: python.exe on Mac OS X!?
The default file system on MacOSX is case insensitive. As a result the .exe extension is required to disambiguate the generated executable from the Python directory in the source distro. OK. I got it. -- http://mail.python.org/mailman/listinfo/python-list
Re: Finding name of running script
Thanks! That's os.path.basename() I guess. It's better, but still complex. I have a _nof_ = argv[0].split(sep)[-1] in my script template and use it under the usage() function to tell what the script does, like: cf.py counts files in directory or directory structure If I change the filename, I want it to be automatically reflected when running the script. That's the motivation. I have the feeling that I came a cross some very simple way to extract the filename, but I can't find my mental note ;-) -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
On Sun, 17 Apr 2005 15:02:12 -0700, Brian Sabbey
[EMAIL PROTECTED] wrote:
Brian Sabbey wrote:
I'm kicking myself for the first example I gave in my original post in
this thread because, looking at it again, I see now that it really gives
the wrong impression about what I want thunks to be in python. The
'thunkit' function above shouldn't be in the same namespace as the thunk.
It is supposed to be a re-usable function, for example, to acquire and
release a resource. On the other hand, the 'foo' function is supposed to
be in the namespace of the surrounding code; it's not re-usable. So your
example above is pretty much the opposite of what I was trying to get
across.
This would explain why I'm having trouble seeing it then.
def pickled_file(thunk, name):
f = open(name, 'r')
l = pickle.load(f)
f.close()
thunk(l)
f = open(name, 'w')
pickle.dump(l, f)
f.close()
Now I can re-use pickled_file whenever I have to modify a pickled file:
do data in pickled_file('pickled.txt'):
data.append('more data')
data.append('even more data')
In my opinion, that is easier and faster to write, more readable, and less
bug-prone than any non-thunk alternative.
The above looks like it's missing something to me. How does 'data'
interact with 'thunk(l)'? What parts are in who's local space?
This might be the non-thunk version of the above.
def pickled_file(thunk, name):
f = open(name, 'r')
l = pickle.load(f)
f.close()
thunk(l)
f = open(name, 'w')
pickle.dump(l, f)
f.close()
def data_append(L):
L.append('more data')
L.append('still more data')
pickled_file(data_append, name)
I don't think I would do it this way. I would put the data
list in a class and add a method to it to update the pickle file. Then
call that from any methods that update the data list.
def with_file: # no argument list, local group.
f = open(filename)
t = callback(f)
f.close
def my_read(f):
return f.read()
callback = my_read
filename = 'filename'
do with_file
This wouldn't work since with_file wouldn't be re-usable. It also doesn't
get rid of the awkwardness of defining a callback.
As long as the name with_file isn't rebound to something else it could
be used as often as needed. I admit there are better ways to do it
though.
Cheers,
Ron
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Re: ANN: Veusz 0.5 - a scientific plotting package
Jeremy Sanders [EMAIL PROTECTED] writes: Veusz 0.5 - Velvet Ember Under Sky Zenith - http://home.gna.org/veusz/ Veusz is a scientific plotting package written in Python (currently 100% Python). It uses PyQt for display and user-interfaces, and numarray for handling the numeric data. Veusz is designed to produce publication-ready Postscript output. Just curious how veusz compares to other python plotting libraries, such as matplotlib... Dan -- http://mail.python.org/mailman/listinfo/python-list
Re: Pattern Matching Given # of Characters and no String Input; use RegularExpressions?
On 17 Apr 2005 18:12:19 -0700, [EMAIL PROTECTED] (Synonymous) wrote: I will look for a Left$(str) function that looks at the first X characters for python :)). Wild goose chase alert! AFAIK there isn't one. Python uses slice notation instead of left/mid/right/substr/whatever functions. I do suggest that instead of looking for such a beastie, you read this section of the Python Tutorial: 3.1.2 Strings. Then, if you think that that was a good use of your time, you might like to read the *whole* tutorial :)) HTH, John -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Suite-Based Keywords - syntax proposal
On 17 Apr 2005 09:27:34 -0700, Kay Schluehr [EMAIL PROTECTED] wrote: Exactly. Except the above example is from the day-old-bread items-tuple-returning version of :: ;-) And with an ordered dict subtype there is no need for the generator expression either, since there is a values method for dicts (which in the subtype would preserve order). E.g., x = property(*seq) where: seq = (:: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ).values()) Or more directly: x = property(*(:: def get_x(): return self.__x def set_x(value): self.__x = value del_x = None doc = I'm the 'x' property. ).values()) Hmmm ... now You eliminate where completely in favor for '::'. This may be reasonable because '::' is stronger and less context dependent. But on the other hand it may be also reasonable to eliminate '::' towards a stronger where ;) x = property(**kw) where kw: doc = I'm the 'x' property. def fget(self): return self.__x x = property(*args) where args: def fget(self): return self.__x fset = None fdel = None doc = I'm the 'x' property. I like this. But how would you put where args: and where kw: if you needed both? also, is it looking back to see the '*' or '**' to do (::x=1).values vs. (::x=1) and how about (::x=1).keys() or (::x=1).items() ? And what if you wanted to pass (::x=1) as a dict object without ** expansion into a keyword dict? Maybe we need asterisks on both ends. e.g., foo(dct, values, *args, **kw): where **dct: x=1 where *values: x=2 where *args: x=3 where **kw: x=4 But that still doesn't give you, e.g., foo(keys) where: keys=sorted((:: from interesting.module import * ).keys()) I like clean sugar, but I still want to be able to get at the general primitives to compose them in ways that can't be anticipated until a use case comes up. And then if the primitives are inaccessible, one is out of luck or doomed to workaround hacking ;-) Put definitions into a list: l = list(*args) where args: def fget(self): return self.__x doc = I'm the 'x' property. Nest suites: x = property(*args) where args: t = tuple(*t) where t: def fget(self): return self.__x fset = None fdel = None doc = I'm the 'x' property. Evaluate conditions: if f(*args)==1 where args: x = 1 y = 2 I think this version is more mainstream syntax ( and without braces and additional punctuation ) than the unary prefix operator '::' which drops statements into expressions within expressions. I like this mainstream syntax for ordinary use cases, but as mentioned, I'd still like to have primitives accessible. I don't see why both couldn't live in harmony ;-) Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: Finding name of running script
runes wrote: Thanks! That's os.path.basename() I guess. It's better, but still complex. Yea murphy's typo ;) I have a _nof_ = argv[0].split(sep)[-1] in my script template and use it under the usage() function to tell what the script does, like: cf.py counts files in directory or directory structure If I change the filename, I want it to be automatically reflected when running the script. That's the motivation. Generally I do it the very same way just spell it different. os.path.basename(sys.argv[0]) I have the feeling that I came a cross some very simple way to extract the filename, but I can't find my mental note ;-) Maybe you found some black magic ;) M.E.Farmer -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
Brian Sabbey wrote:
used, but rarely is because doing so would be awkward. Probably the
simplest real-world example is opening and closing a file. Rarely will
you see code like this:
def with_file(callback, filename):
f = open(filename)
callback(f)
f.close()
def print_file(file):
print file.read()
with_file(print_file, 'file.txt')
For obvious reasons, it usually appears like this:
f = open('file.txt')
print f.read()
f.close()
Normally, though, one wants to do a lot more than just print the file.
There may be many lines between 'open' and 'close'. In this case, it is
easy to introduce a bug, such as returning before calling 'close', or
re-binding 'f' to a different file (the former bug is avoidable by using
'try'/'finally', but the latter is not). It would be nice to be able to
avoid these types of bugs by abstracting open/close. Thunks allow you
to make this abstraction in a way that is more concise and more readable
than the callback example given above:
do f in with_file('file.txt'):
print f.read()
Thunks are also more useful than callbacks in many cases since they
allow variables to be rebound:
t = no file read yet
do f in with_file('file.txt'):
t = f.read()
Using a callback to do the above example is, in my opinion, more difficult:
def with_file(callback, filename):
f = open(filename)
t = callback(f)
f.close()
return t
def my_read(f):
return f.read()
t = with_file(my_read, 'file.txt')
Definitely put this example into the PEP. I didn't really understand
what you were suggesting until I saw this example. All the other ones
you gave just confused me more.
When I see 'do', it reminds me of 'do loops'. That is 'Do' involves
some sort of flow control. I gather you mean it as do items in a
list, but with the capability to substitute the named function. Is
this correct?
I used 'do' because that's what ruby uses for something similar. It can
be used in a flow control-like way, or as an item-in-a-list way.
Please spend some time in the PEP explaining why you chose the keywords
you chose. They gave me all the wrong intuitions about what was
supposed to be going on, and really confused me. I also got mixed up in
when you were talking about parameters to the thunk, and when you were
talking about parameters to the function that is called with the thunk
as a parameter.
I'd also like to see you start with the full example syntax, e.g.:
do unpack_list in returnval = callable(params):
code
And then explain what each piece does more carefully. Something like:
When a do-statement is executed, first callable is called with the
parameters params, augmented by the thunk object, e.g.
do func(4, b=2):
...
would call
func(thunk_obj, 4, b=2)
Next, the body of the function is executed. If the thunk object is
called, then code will be executed with the names in unpack_list
bound to the objects with which the thunk was called, e.g.
def func(thunk):
thunk(1, y=2)
do x, y, z=4 in func():
print x, y, z
would call:
func(thunk_obj)
thunk(1, y=2)
and thus x, y and z would be bound to 1, 2 and 4 and the body of the
thunk would be executed, printing 1 2 4.
The code in callable is then resumed, and the process is repeated
until callable returns. Note that this means that each additional
call to the thunk object will cause another execution of code, with
potentially different bindings for the names in unpack_list.
When the function finally returns, the return value will be bound to
returnval, e.g.:
def func(thunk):
thunk()
thunk()
return True
do r = func():
print thunk called
print r
would print thunk called twice as the body of the thunk is executed
for each call to thunk() in func, and then would print True in the
code following the do-statement.
Not sure if I actually understood everything right, but you definitely
need a much more throrough walkthrough of what happens with a thunk --
it's not clear at all from the current pre-PEP.
STeVe
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Re: python.exe on Mac OS X!?
Rodney Maxwell wrote: executable produced was 'python.exe'. Can someone tell me whether this is a bug, feature, or UserError? I'm not sure. Why don't you grab the binary? http://www.python.org/ftp/python/2.4.1/MacPython-OSX-2.4.1-1 .dmg Because I need to keep multiple versions of Python on this machine, and as far as I can tell the binary installer overwrites the default installed version. I could be wrong. You are wrong. It installs alongside. -- Robert Kern [EMAIL PROTECTED] In the fields of hell where the grass grows high Are the graves of dreams allowed to die. -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
trying to parse a file...
hi, i'm trying to modify an app (gforge) that uses python to do some file parsing/processing... i have the following shell file that uses python. if i understand it correctly, it's supposed to modify the 'viewcvs.conf' file, and replace/update the section with 'svn_roots'. it isn't working correctly... can anybody tell me what i need to do? basically, i'd like to continually add to the svn_root: block with an additional line as required. also, can someone tell me what i'd need to do, if i wanted to remove a line of text from the 'svn_root' block if i had a given 'test_x:' thanks bruce [EMAIL PROTECTED] --- viewcvs.conf: . . . # # This setting specifies each of the Subversion roots (repositories) # on your system and assigns names to them. Each root should be given # by a name: path value. Multiple roots should be separated by # commas and can be placed on separate lines. # #svn_roots = test2: /svn-gforge/uploadsvn svn_roots = test5: /gforge-svn/test7/svn, test2: /gforge-svn/test7/svn, test3: /gforge-svn/test7/svn, # The 'root_parents' setting specifies a list of directories in which # any number of repositories may reside. Rather than force you to add . . . --- [EMAIL PROTECTED] bin]# cat test.sh --- #! /bin/sh python EOF import sys import os import string import ConfigParser r = ConfigParser.RawConfigParser () r.read (/etc/viewcvs/viewcvs.conf) r.set (general,svn_roots,) l = os.listdir (/var/lib/gforge/chroot/svnroot) l2 = [] for d in l: l2.append (d + : svn://localhost/ + d) r.set (general,svn_roots,string.join (l2, ', ')) r.set (general,cvs_roots,) r.set (general,default_root, l [0]) r.write (open (/var/lib/gforge/etc/viewcvs.conf, w)) EOF sed 's,pathname = CONF_PATHNAME .*,pathname = /var/lib/gforge/etc/viewcvs.conf,' \ /usr/lib/python2.3/site-packages/viewcvs/viewcvs.py /var/lib/gforge/etc/viewcvs.py --- -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Suite-Based Keywords - syntax proposal
Kay Schluehr wrote: Hmmm ... now You eliminate where completely in favor for '::'. This may be reasonable because '::' is stronger and less context dependent. But on the other hand it may be also reasonable to eliminate '::' towards a stronger where ;) x = property(**kw) where kw: doc = I'm the 'x' property. def fget(self): return self.__x x = property(*args) where args: def fget(self): return self.__x fset = None fdel = None doc = I'm the 'x' property. [snip] I think this version is more mainstream syntax ( and without braces and additional punctuation ) than the unary prefix operator '::' which drops statements into expressions within expressions. So the object of a where is then always an ordered dict? If so, then I guess I like this proposal best so far. However, it does seem to have the problem that you can't have any additional local variables so, for example, list comprehensions are probably not usable... Or can you still drop the argument to where and just use the names directly? E.g.: x = property(fget=fget, doc=doc) where: doc = I'm the 'x' property. def fget(self): return self.__x STeVe -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
Ron_Adam wrote:
def pickled_file(thunk, name):
f = open(name, 'r')
l = pickle.load(f)
f.close()
thunk(l)
f = open(name, 'w')
pickle.dump(l, f)
f.close()
Now I can re-use pickled_file whenever I have to modify a pickled file:
do data in pickled_file('pickled.txt'):
data.append('more data')
data.append('even more data')
In my opinion, that is easier and faster to write, more readable, and less
bug-prone than any non-thunk alternative.
The above looks like it's missing something to me. How does 'data'
interact with 'thunk(l)'? What parts are in who's local space?
Your example below explains it well, with 'data' renamed as 'L'. The
scope of bindings are the same in both examples, with the exception that
'data' is in the outermost namespace in the above example, and 'L' is
local to the function 'data_append' in the below example.
This might be the non-thunk version of the above.
yes
def pickled_file(thunk, name):
f = open(name, 'r')
l = pickle.load(f)
f.close()
thunk(l)
f = open(name, 'w')
pickle.dump(l, f)
f.close()
def data_append(L):
L.append('more data')
L.append('still more data')
pickled_file(data_append, name)
I don't think I would do it this way. I would put the data
list in a class and add a method to it to update the pickle file. Then
call that from any methods that update the data list.
I also wouldn't do it that way. I don't see a class as being much better,
though. If I understand you correctly, with classes you would have
something like:
p = Pickled('pickled.txt')
p.load()
p.data.append('more data')
p.data.append('even more data')
p.dump()
This has the same issues as with opening and closing files: losing the
'dump', having to always use try/finally if needed, accidentally
re-binding 'p', significantly more lines. Moreover, class 'Pickled' won't
be as readable as the 'pickled_file' function above since 'load' and
'dump' are separate methods that share data through 'self'.
The motivation for thunks is similar to the motivation for generators--
yes, a class could be used instead, but in many cases it's more work than
should be necessary.
-Brian
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Re: pre-PEP: Simple Thunks
On Sun, 17 Apr 2005 15:32:56 -0700, Brian Sabbey [EMAIL PROTECTED] wrote: Bengt Richter wrote: Hm, one thing my syntax does, I just noticed, is allow you to pass several thunks to a thunk-accepter, if desired, e.g., (parenthesizing this time, rather than ending ():suite with dedented comma) each( ((i): # normal thunk print i), ((j): # alternative thunk rejectlist.append(j)), [1,2]) snip I see that it might be nice to be able to use multiple thunks, and to be able to specify the positions in the argument list of thunks, but I think allowing a suite inside parentheses is pretty ugly. One reason is that it is difficult to see where the suite ends and where the argument list begins again. I'm not sure even what the syntax would be exactly. I suppose the suite would always have to be inside its own parentheses? Also, you wind up with these closing parentheses far away from their corresponding open parentheses, which is also not pretty. It's getting too Lisp-like for my tastes. Having had a past love affair (or at least fling) with scheme, that doesn't bother me so much ;-) The where specifier syntax might help, e.g., each(thk1, thk2, [1, 2]) where: thk1 = (i): # normal thunk print i thk2 = (j): # alternative thunk rejectlist.append(j) This still uses my (arglist):suite expression for thunks but they don't need to be parenthesized, because their suites terminate with normal dedenting under the where: suite I.e., the 'p' of 'print i' is the left edge of the (i): suite and thus the 't' of 'thk2 = ...' ends the (i): suite. The (j): suite left edge is at the 'r' of 'rejectlist'... so anything to the left of that (excluding comments) will end the (j): suite, like normal indentation. I could have used dedent termination in the previous example too by moving the commas around to let them trigger dedent level out of the preceding suite, e.g., with args evaluated in place again: each((i): # normal thunk print i ,(j): # alternative thunk rejectlist.append(j) ,[1,2]) Of course, if you want lispy, the above simple thunks can be done in a oneliner: each(((i):print i), ((j):rejectlist.append(j)), [1,2]) I personally like the power of being able to write that, but given a clean sugar alternative, I would use it. But if it's an exclusive-or choice, I'll take primitives over sugar, because sugar never covers all the useful combinations of primitives that will turn up later. Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with unpack hex to decimal
Jonathan Brady wrote:
[EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hello,
I was looking at this:
http://docs.python.org/lib/module-struct.html
and tried the following
import struct
struct.calcsize('h')
2
struct.calcsize('b')
1
struct.calcsize('bh')
4
I would have expected
struct.calcsize('bh')
3
what am I missing ?
Not sure, however I also find the following confusing:
struct.calcsize('hb')
3
struct.calcsize('hb') == struct.calcsize('bh')
False
I could understand aligning to multiples of 4, but why is 'hb' different
from 'bh'?
Evidently, shorts need to be aligned at an even address on your
platform. Consider the following layout, where `b' represents the signed
char, `h' represents the bytes occupied by the short and `X' represents
unused bytes (due to alignment.
'bh', a signed char followed by a short would look like:
bXhh -- or four bytes, but 'hb', a short followed by a signed char would be:
hhb (as `char' and its siblings have no alignment requirements)
HTH,
--ag
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http://it-matters.blogspot.com (new post 12/5)
http://www.cafepress.com/goldsays
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Apache mod_python
I've been writing a server application in Python. The app listens on a socket and interfaces to a database. Now I'd like to write a web application to also access the database. It seems natural to use Python. I've installed mod_python (Debian libapache2-mod-python2.3, mod_python 3.1.3-4). My question is, how mature/stable is mod_python? Is it suitable for a production environment? The documentation is a bit lacking, and I've found some errors in the demo example where it looks like the link should work, but it doesn't. (Could well be something I'm doing.). I've also noted that there's still work being done on it. Thanks. Dan -- http://mail.python.org/mailman/listinfo/python-list
Slight discrepancy with filecmp.cmp
Hi All-- I noticed recently that a few of the jpgs from my digital cameras have developed bitrot. Not a real problem, because the cameras are CD Mavicas, and I can simply copy the original from the cd. Except for the fact that I've got nearly 25,000 images to check. So I wrote a set of programs to both index the disk versions with the cd versions, and to compare, using filecmp.cmp(), the cd and disk version. Works fine. Turned up several dozen files that had been inadvertantly rotated or saved with the wrong quality, various fat-fingered mistakes like that. However, it didn't flag the files that I know have bitrot. I seem to remember that diff uses a checksum algorithm on binary files, not a byte-by-byte comparison. Am I wrong? If I am, what then is the source of the problem in my jpg images where it looks like a bit or two has been shifted or added; suddenly, there's a line going through the picture above which it's normal, and below it either the color has changed (usually to pinkish) or the remaining raster lines are all shifted either right or left? Any ideas? Metta, Ivan -- Ivan Van Laningham God N Locomotive Works http://www.andi-holmes.com/ http://www.foretec.com/python/workshops/1998-11/proceedings.html Army Signal Corps: Cu Chi, Class of '70 Author: Teach Yourself Python in 24 Hours -- http://mail.python.org/mailman/listinfo/python-list
Re: Compute pi to base 12 using Python?
PS. Redirecting with from a script whose interpreter was started by windows extension association doesn't work on some version of windows. To be safe, invoke the interpreter explicitly, e.g., python myscript.py [whatever args here] pi3003.txt Thanks very much for this. What kind of args could I use here? Any that your script allows or understands. an example: python c:/Python22/Lib/PySourceColor.py -i- -s -l c:/MyFile.py c:/tmp/myfile.html A few things that might help you write a well behaved script: if sys.stdin.isatty(): direct else: redirected This snippet can determine if you have redirected IO. I just found this and it looks informative. http://www.jpsdomain.org/windows/redirection.html hth, M.E.Farmer -- http://mail.python.org/mailman/listinfo/python-list
