Re: pre-PEP: Simple Thunks
Greg Ewing wrote:
Brian Sabbey wrote:
do f in with_file('file.txt'):
print f.read()
I don't like this syntax. Try to read it as an English sentence:
Do f in with file 'file.txt'. Say what???
To sound right it would have to be something like
with_file('file.txt') as f do:
print f.read()
This is still strange since f is the arguments the thunk was called
with, e.g. the current syntax is basically:
do unpack_list in returnval = callable(params):
code
I don't really know a more readable sequence of keywords, though someone
suggested 'with' and 'from', which might read something like:
with unpack_list from callable(params):
code
which looks okay to me, though I'm not sure that 'with' makes it clear
that this is not a normal block... I also find readability problems
when I try to stick returnval back in.
One of the other issues is that, with the current proposal, the thunk
can be called multiple times within a function, so the keywords have to
make sense both with a single iteration interpretation and a multiple
iteration interpretation... Makes it even harder...
STeVe
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Why Python does *SLICING* the way it does??
Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). Many people don't like idea that 5th element is not invited. (BTW, yes I'm aware of the explanation where slicing is shown to involve slices _between_ elements. This doesn't explain why this is *best* way to do it.) Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: Enumerating formatting strings
Steve Holden wrote: I've been wondering whether it's possible to perform a similar analysis on non-mapping-type format strings, so as to know how long a tuple to provide, I just tried an experiment, and it doesn't seem to be possible. The problem seems to be that it expects the arguments to be in the form of a tuple, and if you give it something else, it wraps it up in a 1-element tuple and uses that instead. This seems to happen even with a custom subclass of tuple, so it must be doing an exact type check. So it looks like you'll have to parse the format string. -- Greg Ewing, Computer Science Dept, University of Canterbury, Christchurch, New Zealand http://www.cosc.canterbury.ac.nz/~greg -- http://mail.python.org/mailman/listinfo/python-list
Re: New to Tkinter...
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Re: Why Python does *SLICING* the way it does??
[EMAIL PROTECTED] Many people I know ask why Python does slicing the way it does. Half open intervals are just one way of doing things. Each approach has its own merits and issues. Python's way has some useful properties: * s == s[:i] + s[i:] * len(s[i:j]) == j-i # if s is long enough OTOH, it has some aspects that bite: * It is awkward with negative strides such as with s[4:2:-1]. This was the principal reason for introducing the reversed() function. * It makes some people cringe when they first see it (you're obviously in that group). I suspect that whether it feels natural depends on your previous background and whether you're working in an environment with arrays indexed from one or from zero. For instance, C programmers are used to seeing code like: for(i=0 ; in; i++) a[i]=f(i); In contrast, a BASIC programmer may be used to FOR I = 1 to N: a[I]=f(I); NEXT.Hence, the C coders may find Python's a[:n] to be more natural than BASIC programmers. As long as a language is consistent about its approach, you just get used to it and it stops being an issue after a few days. Raymond Hettinger -- http://mail.python.org/mailman/listinfo/python-list
Re: How to run Python in Windows w/o popping a DOS box?
[EMAIL PROTECTED] (Bengt Richter) writes: I would try right-clicking the shortcut icon and selecting properties, then select the shortcut tab and edit the target string with s/python/pythonw/ and then click ok. Thanks! I'll try that tomorrow. I never would have figured that out. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to Convert a makefile to Python Script
Thanks For Your Help Regards rkoida -- http://mail.python.org/mailman/listinfo/python-list
Re: Array of Chars to String
Michael Spencer wrote: def func_join(s, letters): ... return .join(letter for letter in s if letter in set(letters)) Make that def func_join(s, letters): letter_set = set(letters) return .join(letter for letter in s if letter in letter_set) for a fair timing of a set lookup as opposed to set creation. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing to stdout and a log file
Mike wrote: I would like my 'print' statements to send its output to the user's screen and a log file. This is my initial attempt: class StdoutLog(file): def __init__(self, stdout, name='/tmp/stdout.log', mode='w',bufsize=-1): super(StdoutLog, self).__init__(name,mode,bufsize) self.stdout = stdout def write(self, data): self.stdout.write(data) What happens when you do a self.stdout.flush() here? self.write(data) import sys sys.stdout = StdoutLog(sys.stdout) print 'STDOUT', sys.stdout When the program is run the string is written to the log file but nothing appears on my screen. Where's the screen output? It looks like the superclass's write() method is getting called instead of the StdoutLog instance's write() method. The python documentation says 'print' should write to sys.stdout.write() but that doesn't seem to be happening. Any idea what's going one? Or ideas on how to debug this? Thanks, Mike I had the same problem (writing to file and stdout with print) and my solution was *not* to subclass file and instead add a self.outfile=file(...) to the constructor. HTH, Wolfram -- http://mail.python.org/mailman/listinfo/python-list
Re: pre-PEP: Simple Thunks
Ron_Adam [EMAIL PROTECTED] writes: Here's yet another way to do it, but it has some limitations as well. import pickle def pickle_it(filename, obj, commands): try: f = open(filename, 'r') obj = pickle.load(f) f.close() except IOError: pass for i in commands: i[0](i[1]) f = open(filename, 'w') pickle.dump(obj, f) f.close() file = 'filename' L = [] opps = [ (L.append,'more data'), (L.append,'even more data') ] pickle_it(file, L, opps) Um - it doesn't look like this will work. You pass L in as the obj paremeter, and then it gets changed to the results of a pickle.load. However, you call L.append in the for loop, so the data will be appended to L, not obj. You'll lose an list elements that were in the pickle. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: Enumerating formatting strings
Greg Ewing wrote: Steve Holden wrote: I've been wondering whether it's possible to perform a similar analysis on non-mapping-type format strings, so as to know how long a tuple to provide, I just tried an experiment, and it doesn't seem to be possible. The problem seems to be that it expects the arguments to be in the form of a tuple, and if you give it something else, it wraps it up in a 1-element tuple and uses that instead. This seems to happen even with a custom subclass of tuple, so it must be doing an exact type check. No, it doesn't do an exact type check, but always calls the tuple method: class Tuple(tuple): ... def __getitem__(self, index): ... return 42 ... %r %r % Tuple(ab) # would raise an exception if wrapped 'a' 'b' So it looks like you'll have to parse the format string. Indeed. Peter -- http://mail.python.org/mailman/listinfo/python-list
To decode the Subject =?iso-8859-2?Q?=... in email in python
When parsing messages using python's libraries email and mailbox, the subject is often encoded using some kind of = notation. Apparently, the encoding used in this notation is specified like =?iso-8859-2?Q?=... or =?iso-8859-2?B?=. Is there a python library function to decode such a subject, returning a unicode string? The use would be like human_readable = cool_library.decode_equals(message['Subject']) Thank you, Dan -- http://mail.python.org/mailman/listinfo/python-list
Python instances
Hi, How do python instances work? Why does the code at the end of my posting produce this output: list in a: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] list in b: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] instead of list in a: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] list in b: [] class MyClass: list = [] def add(self, x): self.list.append(x) def printer(self): print self.list a = MyClass() b = MyClass() for n in range(10): a.add(n) print list in a: a.printer() print list in b: b.printer() /H -- http://mail.python.org/mailman/listinfo/python-list
Re: Python instances
Hi, class MyClass: list = [] you have list defined as a classmember, not an instancemember. So list ist defined ONCE for all instances. Try this instead: class MyClass: def __init__(self): self.list = [] [...] and use self.list ... HtH, Roland -- http://mail.python.org/mailman/listinfo/python-list
long time we haven't spoken ;)
Daayuum bro You'll never guess what happened to me last week. Basically found a 18 + date site that doesn't charge anything. So many couples, guys and girls are there messaging and meeting eachother. And I'm certain there is someone (or more than one) for you. Although most of them want one-nighters, there are also those who like it serious. Whatever you feel like pretty much ;-) http://www.fernirr.com/a5/ PS:no.more? http://www.fernirr.com/rmv/ -- http://mail.python.org/mailman/listinfo/python-list
Re: To decode the Subject =?iso-8859-2?Q?=... in email in python
Dan Polansky wrote: When parsing messages using python's libraries email and mailbox, the subject is often encoded using some kind of = notation. Apparently, the encoding used in this notation is specified like =?iso-8859-2?Q?=... or =?iso-8859-2?B?=. Is there a python library function to decode such a subject, returning a unicode string? The use would be like human_readable = cool_library.decode_equals(message['Subject']) parts = email.Header.decode_header(header) new_header = email.Header.make_header(parts) human_readable = unicode(new_header) -- hilsen/regards Max M, Denmark http://www.mxm.dk/ IT's Mad Science -- http://mail.python.org/mailman/listinfo/python-list
Re: Python instances
Guess i shouldn't think of the __init__(self) function as a constructor then. Thanks. /H -- http://mail.python.org/mailman/listinfo/python-list
Fwd: Memory leak in python
Hi Nick, Thanks for reply... Please include me in reply. Currently i am not in the list (i will subscribe soon) I upgarded to 2.4.1 - still the same issue. Nick Thats not a lot of leak - have you done that over a longer time period? Abhi I have tried for 4 days. It has reached 150MB. Nick Are there any objects in gc.garbage? gc.set_debug(gc.DEBUG_LEAK) gc.get_debug( ) 62 gc.collect() 0 gc.garbage [] Abhi There is none. Nick Are you writing objects with __del__ methods? If so then that is your problem probably. Abhi I have not written any __del__ methods. Nick Have you written any C extension modules in C? Yes. Many - All of them are called only when the app starts. And never called again. Till then it is stable only - 16MB used. I have tried following - let me know if you need any more details.. and want me to try something. 1) I found a sizer python program. Which gives me the module which is growing. It indicates that __main__ is growing. __main__': 4000774 2) I tried following.. (not smart but..) def f(): c = gc.get_objects() j = 0 for i in c: j = j + 1 try: tmp = len(i) if tmp 1000: print (c[%d]) (%d), % (j-1, tmp) except: pass it prints me as folows: l(c[175]) (7336), l(c[12475]) (1260), l(c[12477]) (1260), l(c[12479]) (1381), l(c[12481]) (1381), l(c[34159]) (1200), l(c[37144]) (28234), l(c[37191]) (28286), type(c[37191]) type 'dict' for k,v in c[37164].items(): ...print k, v ...b = b + 1 ...if b 30: ... break ... 1085115764 620 1080048556 2 1085045932 4 1085146316 1 1085246700 2 1090615060 9 1089571940 2 1090519084 2 1090876932 234 1093456364 48 1085168140 2 1089964748 6 1089994828 0 1090095684 69 1076932268 2 1085014108 6 1080092204 10 108412 1 1118543628 48 1089994860 6 1076731524 6 1079640188 3 1084883076 15 1079712492 1 1118459244 64 1080295564 1 1076522028 4 1085211788 2 1076887700 20 1076729756 70 1091012236 2 This two dict in the last is growing slowly.. I am not maintaing any dict with such indices and value. Any clue? Please let me know what else to check and how! At the time i am ending this.. module size.. '__main__': 7926830, Thanks, Abhishek Note: forwarded message attached. __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---BeginMessage--- Hi, using python2.2.2 I am seeing that the python application is very slowly eating up the memory. i need help to indentify it. It start with 11MB and keeps growing by 1 MB around every 30mins. #top | grep python 10351 root 15 0 26584 25M 3896 S 0.5 0.8 46:05 1 python2 10351 root 15 0 26592 25M 3896 S 3.5 0.8 46:06 1 python2 10351 root 15 0 26596 25M 3896 S30.9 0.8 46:07 0 python2 10351 root 15 0 26608 25M 3896 S73.0 0.8 46:11 0 python2 10351 root 15 0 26612 25M 3896 S73.2 0.8 46:15 0 python2 10351 root 15 0 26616 25M 3896 S78.6 0.8 46:18 1 python2 10351 root 15 0 26620 25M 3896 S78.4 0.8 46:22 1 python2 10351 root 15 0 26620 25M 3896 S77.4 0.8 46:26 1 python2 10351 root 15 0 26620 25M 3896 S73.2 0.8 46:30 1 python2 10351 root 15 0 26620 25M 3896 S65.8 0.8 46:33 1 python2 10351 root 15 0 26620 25M 3896 S43.3 0.8 46:35 1 python2 10351 root 15 0 26620 25M 3896 S53.8 0.8 46:38 1 python2 10351 root 15 0 26620 25M 3896 S26.3 0.8 46:39 1 python2 10351 root 15 0 26636 26M 3896 S33.5 0.8 46:41 1 python2 10351 root 15 0 26640 26M 3896 S25.7 0.8 46:42 1 python2 10351 root 15 0 26656 26M 3896 S23.9 0.8 46:44 1 python2 10351 root 15 0 26656 26M 3896 S11.7 0.8 46:44 1 python2 10351 root 15 0 26660 26M 3896 S10.7 0.8 46:45 1 python2 10351 root 15 0 26668 26M 3896 S 3.7 0.8 46:45 1 python2 10351 root 15 0 26668 26M 3896 S 1.7 0.8 46:45 1 python2 10351 root 15 0 26668 26M 3896 S 0.7 0.8 46:45 1 python2 10351 root 15 0 26668 26M 3896 S 0.3 0.8 46:45 1 python2 10351 root 15 0 26684 26M 3896 S 4.5 0.8 46:45 1 python2 10351 root 15 0 26688 26M 3896 S 2.1 0.8 46:45 1 python2 let me know how to approch this. gc.collect - does not collect anything. Thanks, Abhishek __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---End Message--- -- http://mail.python.org/mailman/listinfo/python-list
Re: Python instances
Guess i shouldn't think of the __init__(self) function as a constructor then. __init__ is THE constructor in Python -- _ Laszlo Nagy web: http://designasign.biz IT Consultantmail: [EMAIL PROTECTED] Python forever! -- http://mail.python.org/mailman/listinfo/python-list
Re: To decode the Subject =?iso-8859-2?Q?=... in email in python
# [EMAIL PROTECTED] / 2005-04-20 00:30:35 -0700:
When parsing messages using python's libraries email and mailbox, the
subject is often encoded using some kind of = notation. Apparently, the
encoding used in this notation is specified like =?iso-8859-2?Q?=... or
=?iso-8859-2?B?=.
That's RFC 2047 encoding, both examples introduce an ISO8859-2
string, the first variant says it's ascii-ized using
Quoted-Printable, the other says the string is Base64-encoded.
Is there a python library function to decode such a
subject, returning a unicode string? The use would be like
human_readable = cool_library.decode_equals(message['Subject'])
quoting from http://docs.python.org/lib/module-email.Header.html
from email.Header import decode_header
decode_header('=?iso-8859-1?q?p=F6stal?=')
[('p\xf6stal', 'iso-8859-1')]
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You don't know, man. You don't KNOW.
Cause you weren't THERE. http://bash.org/?255991
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Re: Enumerating formatting strings
On Wed, 20 Apr 2005 09:14:40 +0200, Peter Otten [EMAIL PROTECTED] wrote:
Greg Ewing wrote:
Steve Holden wrote:
I've been wondering whether it's possible to perform a similar analysis
on non-mapping-type format strings, so as to know how long a tuple to
provide,
I just tried an experiment, and it doesn't seem to be possible.
The problem seems to be that it expects the arguments to be
in the form of a tuple, and if you give it something else,
it wraps it up in a 1-element tuple and uses that instead.
This seems to happen even with a custom subclass of tuple,
so it must be doing an exact type check.
No, it doesn't do an exact type check, but always calls the tuple method:
class Tuple(tuple):
... def __getitem__(self, index):
... return 42
...
%r %r % Tuple(ab) # would raise an exception if wrapped
'a' 'b'
So it looks like you'll have to parse the format string.
Indeed.
Parse might be a big word for
def tupreq(fmt): return sum(map(lambda s:list(s).count('%'),
fmt.split('%%')))
..
tupreq('%s this %(x)s not %% but %s')
(if it works in general ;-)
Or maybe clearer and faster:
def tupreq(fmt): return sum(1 for c in fmt.replace('%%','') if c=='%')
...
tupreq('%s this %(x)s not %% but %s')
3
Regards,
Bengt Richter
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Re: Python Google Server
Thanks Benji, It returns the results using an ip address - not the google domain. This means IPCop bans it :-( Thanks for the suggestion though. In actual fact the googleCacheServer works quite well. Best Regards, Fuzzy http://www.voidspace.org.uk/python/weblog -- http://mail.python.org/mailman/listinfo/python-list
Re: Proposal: an unchanging URL for Python documentation
On 4/19/05, Skip Montanaro [EMAIL PROTECTED] wrote: ... the documentation for the os steve module would also be available at steve http://python.org/doc/current/lib/module-os.html. Time machine at work? The above URL works for me now. Yup, but it's not all unchanging. Take, for example, http://www.python.org/doc/current/tut/node16.html. I have wanted to steer people towards that page a number of times, and that node number keeps changing. -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python instances
On 20 Apr 2005 00:44:53 -0700, [EMAIL PROTECTED] wrote: Guess i shouldn't think of the __init__(self) function as a constructor then. Thanks. Depends on what you think when you think constructor ;-) Read about both __new__ and __init__. The former is always necessary to create an object, and __init__ may take parameters to define intial state from its parameters, but __new__ does the whole job for immutables. I.e., constructor translates to combination of both if both are present, but __new__ must be always be there and come first. In general there are default methods inherited from object and/or type, the most primitive classes, so you don't have to define them except to customize for your purposes. At least, that's the way I think of it ;-) Regards, Bengt Richter -- http://mail.python.org/mailman/listinfo/python-list
Re: Behaviour of str.split
Greg Ewing wrote: Will McGugan wrote: Hi, I'm curious about the behaviour of the str.split() when applied to empty strings. .split() returns an empty list, however.. .split(*) returns a list containing one empty string. Both of these make sense as limiting cases. Consider a b c.split() ['a', 'b', 'c'] a b.split() ['a', 'b'] a.split() ['a'] .split() [] and **.split(*) ['', '', ''] *.split(*) ['', ''] .split(*) [''] The split() method is really doing two somewhat different things depending on whether it is given an argument, and the end-cases come out differently. You don't really explain *why* they make sense as limiting cases, as your examples are quite different. Consider a*b*c.split(*) ['a', 'b', 'c'] a*b.split(*) ['a', 'b'] a.split(*) ['a'] .split(*) [''] Now how is this logical when compared with split() above? David -- http://mail.python.org/mailman/listinfo/python-list
Re: Enumerating formatting strings
Bengt Richter wrote:
Parse might be a big word for
def tupreq(fmt): return sum(map(lambda s:list(s).count('%'),
fmt.split('%%')))
..
tupreq('%s this %(x)s not %% but %s')
(if it works in general ;-)
Which it doesn't:
def tupreq(fmt): return sum(map(lambda s:list(s).count('%'),
fmt.split('%%')))
...
fmt = %*d
fmt % ((1,) * tupreq(fmt))
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: not enough arguments for format string
Or maybe clearer and faster:
def tupreq(fmt): return sum(1 for c in fmt.replace('%%','') if
c=='%')
...
tupreq('%s this %(x)s not %% but %s')
3
Mixed formats show some interesting behaviour:
%s %(x)s % (1,2)
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: format requires a mapping
class D:
... def __getitem__(self, key):
... return D[%s] % key
...
%s %(x)s % D()
'__main__.D instance at 0x402aaf2c D[x]'
%s %(x)s %s % D()
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: not enough arguments for format string
%s %(x)s %(y)s % D()
'__main__.D instance at 0x402aad8c D[x] D[y]'
That is as far as I got. So under what circumstances is
'%s this %(x)s not %% but %s' a valid format string?
Peter
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Re: xmlrpclib and binary data as normal parameter strings
Richard Brodie [EMAIL PROTECTED] writes: Rune Froysa [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] From http://www.xmlrpc.com/spec :: Any characters are allowed in a string except and , which are encoded as lt; and amp;. A string can be used to encode binary data. the XMLRPC specification is worded pretty loosely. Obviously characters forbidden in XML will be problematic. IMHO that is not obvious. The API-user wants to call a function on a remote server with an arbitrary argument. What the transport-layer does to achieve this should be completly transparent to the user. We already have code that takes care of . Ideally we should do that for other data as well. Unfortunately the XML-spec doesn't allow us to use character references %#x1b;. With the patch below, setting BINARY_AS_STRING=True will cause all strings to be transparently base64-encoded during transport. Unfortunately it will do this for all incoming binary data, thus breaking aplications that explicitly uses the Binary class for this purpose. IMHO the xmlrpc spec should be updated to allow something like this. --- /local/lib/python2.3/xmlrpclib.py 2005-01-10 10:30:43.0 +0100 +++ xmlrpclib.py2005-04-20 09:56:11.0 +0200 @@ -177,6 +177,8 @@ __version__ = 1.0.1 +BINARY_AS_STRING = False + # xmlrpc integer limits MAXINT = 2L**31-1 MININT = -2L**31 @@ -652,6 +654,11 @@ dispatch[FloatType] = dump_double def dump_string(self, value, write, escape=escape): +if BINARY_AS_STRING: +self.write = write +Binary(value).encode(self) +del self.write +return write(valuestring) write(escape(value)) write(/string/value\n) @@ -843,7 +850,10 @@ def end_base64(self, data): value = Binary() value.decode(data) -self.append(value) +if BINARY_AS_STRING: +self.append(value.data) +else: +self.append(value) self._value = 0 dispatch[base64] = end_base64 -- Rune Frøysa -- http://mail.python.org/mailman/listinfo/python-list
goto statement
Dear All, In Python what is equivalent to goto statement regards, praba __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
praba kar wrote: Dear All, In Python what is equivalent to goto statement You shouldn't use goto in high-level languages. Mage -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing to stdout and a log file
flushing stdout has no effect. I've got an implementation that does not subclass file. It's not as nice but it works. -- http://mail.python.org/mailman/listinfo/python-list
Re: Refactoring in Python.
[EMAIL PROTECTED] writes: Investigate the CVS histories of the few 1000s python projects available at www.sourceforge.net I don't work with these guys : -- http://www.pdemb.prv.pl -- http://mail.python.org/mailman/listinfo/python-list
Re: XML parsing per record
On Sun, 17 Apr 2005 02:16:04 +, William Park wrote: Willem Ligtenberg [EMAIL PROTECTED] wrote: I want to parse a very large (2.4 gig) XML file (bioinformatics ofcourse :)) But I have no clue how to do that. Most things I see read the entire xml file at once. That isn't going to work here ofcourse. So I would like to parse a XML file one record at a time and then be able to store the information in another object. How should I do that? Thanks in advance, Willem Ligtenberg A total newbie to python by the way. You may want to try Expat (www.libexpat.org) or Python wrapper to it. You can feed small piece at a time, say by lines or whatever. Of course, it all depends on what kind of parsing you have in mind. :-) Care to post more details? The XML file I need to parse contains information about genes. So the first element is a gene and then there are a lot sub-elements with sub-elements. I only need some of the informtion and want to store it in my an object called gene. Lateron this information will be printed into a file, which in it's turn will be fed into some other program. This is an example of the XML ?xml version=1.0? !DOCTYPE Entrezgene-Set PUBLIC -//NCBI//NCBI Entrezgene/EN NCBI_Entrezgene.dtd Entrezgene-Set Entrezgene Entrezgene_track-info Gene-track Gene-track_geneid9996/Gene-track_geneid Gene-track_status value=secondary1/Gene-track_status Gene-track_current-id Dbtag Dbtag_dbLocusID/Dbtag_db Dbtag_tag Object-id Object-id_id320632/Object-id_id /Object-id /Dbtag_tag /Dbtag Dbtag Dbtag_dbGeneID/Dbtag_db Dbtag_tag Object-id Object-id_id320632/Object-id_id /Object-id /Dbtag_tag /Dbtag /Gene-track_current-id Gene-track_create-date Date Date_std Date-std Date-std_year2003/Date-std_year Date-std_month8/Date-std_month Date-std_day28/Date-std_day Date-std_hour21/Date-std_hour Date-std_minute39/Date-std_minute Date-std_second0/Date-std_second /Date-std /Date_std /Date /Gene-track_create-date Gene-track_update-date Date Date_std Date-std Date-std_year2005/Date-std_year Date-std_month2/Date-std_month Date-std_day17/Date-std_day Date-std_hour12/Date-std_hour Date-std_minute54/Date-std_minute Date-std_second0/Date-std_second /Date-std /Date_std /Date /Gene-track_update-date /Gene-track /Entrezgene_track-info Entrezgene_type value=protein-coding6/Entrezgene_type Entrezgene_source BioSource BioSource_genome value=genomic1/BioSource_genome BioSource_origin value=natural1/BioSource_origin BioSource_org Org-ref Org-ref_taxnameMus musculus/Org-ref_taxname Org-ref_commonhouse mouse/Org-ref_common Org-ref_db Dbtag Dbtag_dbtaxon/Dbtag_db Dbtag_tag Object-id Object-id_id10090/Object-id_id /Object-id /Dbtag_tag /Dbtag /Org-ref_db Org-ref_syn Org-ref_syn_Emouse/Org-ref_syn_E /Org-ref_syn Org-ref_orgname OrgName OrgName_name OrgName_name_binomial BinomialOrgName BinomialOrgName_genusMus/BinomialOrgName_genus BinomialOrgName_speciesmusculus/BinomialOrgName_species /BinomialOrgName /OrgName_name_binomial /OrgName_name OrgName_lineageEukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia; Sciurognathi; Muridae; Murinae; Mus/OrgName_lineage OrgName_gcode1/OrgName_gcode OrgName_mgcode2/OrgName_mgcode OrgName_divROD/OrgName_div /OrgName /Org-ref_orgname /Org-ref /BioSource_org /BioSource /Entrezgene_source Entrezgene_gene Gene-ref /Gene-ref /Entrezgene_gene Entrezgene_gene-source Gene-source Gene-source_srcLocusLink/Gene-source_src Gene-source_src-int9996/Gene-source_src-int Gene-source_src-str29996/Gene-source_src-str2 Gene-source_gene-display value=false/ Gene-source_locus-display value=false/ Gene-source_extra-terms value=false/ /Gene-source /Entrezgene_gene-source
Re: Behaviour of str.split
On Wed, 20 Apr 2005 10:55:18 +0200, David Fraser [EMAIL PROTECTED] wrote:
Greg Ewing wrote:
Will McGugan wrote:
Hi,
I'm curious about the behaviour of the str.split() when applied to
empty strings.
.split() returns an empty list, however..
.split(*) returns a list containing one empty string.
Both of these make sense as limiting cases.
Consider
a b c.split()
['a', 'b', 'c']
a b.split()
['a', 'b']
a.split()
['a']
.split()
[]
and
**.split(*)
['', '', '']
*.split(*)
['', '']
.split(*)
['']
The split() method is really doing two somewhat different things
depending on whether it is given an argument, and the end-cases
come out differently.
You don't really explain *why* they make sense as limiting cases, as
your examples are quite different.
Consider
a*b*c.split(*)
['a', 'b', 'c']
a*b.split(*)
['a', 'b']
a.split(*)
['a']
.split(*)
['']
Now how is this logical when compared with split() above?
The trouble is that s.split(arg) and s.split() are two different functions.
The first is 1:1 and reversible like arg.join(s.split(arg))==s
The second is not 1:1 nor reversible: 'various whitespace'.join(s.split())
== s ?? Not usually.
I think you can do it with the equivalent whitespace regex, preserving the
splitout whitespace
substrings and ''.joining those back with the others, but not with split().
I.e.,
def splitjoin(s, splitter=None):
... return (splitter is None and 'whitespace' or
splitter).join(s.split(splitter))
...
splitjoin('a*b*c', '*')
'a*b*c'
splitjoin('a*b', '*')
'a*b'
splitjoin('a', '*')
'a'
splitjoin('', '*')
''
splitjoin('a bc')
'awhitespacebwhitespacec'
splitjoin('a b')
'awhitespaceb'
splitjoin(' b')
'b'
splitjoin('')
''
splitjoin('*','*')
'*'
Note why that works:
'*'.split('*')
['', '', '', '', '', '']
'*a'.split('*')
['', 'a']
'a*'.split('*')
['a', '']
splitjoin('*a','*')
'*a'
splitjoin('a*','*')
'a*'
Regards,
Bengt Richter
--
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Re: goto statement
On 4/20/05, praba kar [EMAIL PROTECTED] wrote: In Python what is equivalent to goto statement http://docs.python.org/tut/node6.html See, it's those dratted node numbers again. ;-) -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Lex
I have to work on python lexical definition in Lex. I spent lots of my time to find regular expresions written for Lex of Python language but nothing. Can somebody help me? -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Simon Brunning a écrit : On 4/20/05, praba kar [EMAIL PROTECTED] wrote: In Python what is equivalent to goto statement http://docs.python.org/tut/node6.html See, it's those dratted node numbers again. ;-) other equivalents are in http://docs.python.org/tut/node10.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Enumerating formatting strings
On Wed, 20 Apr 2005 11:01:28 +0200, Peter Otten [EMAIL PROTECTED] wrote:
Bengt Richter wrote:
Parse might be a big word for
def tupreq(fmt): return sum(map(lambda s:list(s).count('%'),
fmt.split('%%')))
..
tupreq('%s this %(x)s not %% but %s')
(if it works in general ;-)
Which it doesn't:
D'oh. (My subconscious knew that one, and prompted the if ;-)
def tupreq(fmt): return sum(map(lambda s:list(s).count('%'),
fmt.split('%%')))
...
fmt = %*d
fmt % ((1,) * tupreq(fmt))
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: not enough arguments for format string
But that one it totally spaced on ;-/
Or maybe clearer and faster:
def tupreq(fmt): return sum(1 for c in fmt.replace('%%','') if
c=='%')
...
tupreq('%s this %(x)s not %% but %s')
3
Mixed formats show some interesting behaviour:
%s %(x)s % (1,2)
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: format requires a mapping
class D:
... def __getitem__(self, key):
... return D[%s] % key
...
%s %(x)s % D()
'__main__.D instance at 0x402aaf2c D[x]'
%s %(x)s %s % D()
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: not enough arguments for format string
%s %(x)s %(y)s % D()
'__main__.D instance at 0x402aad8c D[x] D[y]'
That is as far as I got. So under what circumstances is
'%s this %(x)s not %% but %s' a valid format string?
Yeah, I got that far too, some time ago playing % mapping, and
I thought they just didn't allow for mixed formats. My thought then
was that they could pass integer positional keys to another method
(say __format__) on a mapping object that wants to handle mixed formats.
If you wanted the normal str or repr resprensentation of a mapping
object that had a __format__ method, you'd have to do it on the args
side with str(theobject), but you'd have a way. And normal mapping objects
would need no special handling for %s' in a mixed format context.
Regards,
Bengt Richter
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Re: goto statement
On 4/20/05, Maurice Caret [EMAIL PROTECTED] wrote: other equivalents are in http://docs.python.org/tut/node10.html I also missed http://docs.python.org/tut/node5.html#SECTION00520, for the while statement. Those URLs just keeg getting better... -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
trying to understand unicode
Python has a very good support of unicode, utf8, encodings ... But I
have some difficulties with the concepts and the vocabulary. The
documentation is not bad, but for example in reading
http://docs.python.org/lib/module-unicodedata.html
I had a long time to figure out what unicodedata.digit(unichr) would
mean, a simple example is badly lacking.
So I wrote the following script :
#!/usr/bin/env python
Example of use of the unicodedata module
http://docs.python.org/lib/module-unicodedata.html
import unicodedata
import sys
# outcodec = 'latin_1'
outcodec = 'iso8859_15'
if len(sys.argv) 1:
outcodec = sys.argv[1]
for c in range(256):
uc = unichr(c)
uname = unicodedata.name(uc, None)
if uname:
unfd = unicodedata.normalize('NFD', uc).encode(outcodec,
'replace')
unfc = unicodedata.normalize('NFC', uc).encode(outcodec,
'replace')
print str(c).ljust(3), uname.ljust(42), unfd.ljust(2),
unfc.ljust(2), \
unicodedata.category(uc), unicodedata.numeric(uc, None)
and here are some samples of output
44 COMMA , , Po None
45 HYPHEN-MINUS - - Pd None
46 FULL STOP . . Po None
47 SOLIDUS/ / Po None
48 DIGIT ZERO 0 0 Nd 0.0
49 DIGIT ONE 1 1 Nd 1.0
50 DIGIT TWO 2 2 Nd 2.0
It seems that 'Nd' category means Numerical digit doh!
64 COMMERCIAL AT @ @ Po None
65 LATIN CAPITAL LETTER A A A Lu None
66 LATIN CAPITAL LETTER B B B Lu None
'Lu' should read 'Letter upper' ?
94 CIRCUMFLEX ACCENT ^ ^ Sk None
95 LOW LINE _ _ Pc None
96 GRAVE ACCENT ` ` Sk None
97 LATIN SMALL LETTER A a a Ll None
98 LATIN SMALL LETTER B b b Ll None
'Ll' == Letter lower
124 VERTICAL LINE | | Sm None
125 RIGHT CURLY BRACKET} } Pe None
126 TILDE ~ ~ Sm None
160 NO-BREAK SPACE Zs None
161 INVERTED EXCLAMATION MARK ¡ ¡ Po None
What a gap !
245 LATIN SMALL LETTER O WITH TILDEo? õ Ll None
246 LATIN SMALL LETTER O WITH DIAERESISo? ö Ll None
247 DIVISION SIGN ÷ ÷ Sm None
248 LATIN SMALL LETTER O WITH STROKE ø ø Ll None
'Sm' should read 'sign mathematics' ?
I think that such code snippets should be included in the documentation
or in a Wiki.
Regards
Sorry for bad english, I'm not a native speaker.
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Re: goto statement
Mage wrote: praba kar wrote: Dear All, In Python what is equivalent to goto statement You shouldn't use goto in high-level languages. it would be quite useful for debuging porposes -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: (Python newbie) Using XP-SP2/MSVC6: No Python24_d.lib, winzip barfs on Python-2.4.1.tar, cannot download bzip2
Thank you Khalid, OK. (4) (compile using MSVC6) worked. Now working through various issues to do with paths and naming (_d suffix to root for DEBUG, _ prefix to root for SWIG, and I had not spotted that SWIG makes Module.py that imports _Module.pyd but not _Module_d.pyd for DEBUG builds). I'd like to persuade IDLE to use my locally compiled version of Python rather than the one I downloaded, and will find out how eventually. Necessary to keep to a VC6 build of 2.4.1 throughout. Rgds, Bill (an inveterate top poster, I'm afraid). A.B., Khalid [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Okay, let me have another stap at this. As you have probably noticed MSVC6 is no longer actively supported as far as Python 2.4 goes. The official distribution of Python 2.4 for Windows is built using MSVC7.1 (or whatever you wish to call it). We are told that building C extensions with MSVC6 for use in the official Python 2.4 (which uses the MSVCR71) is not safe, and mixing the different runtime libraries that your extension (or my extension) with that which official Python 2.4 uses will/might cause crashes. Google around for details on this. So, what to do? You seem to have four options. 1. Get and use the MSVC7.1 compiler. 2. Get and use the freely distributed MS compiler. 3. Download the Python source[1] and compile it yourself in MSVC6 (there are project files in the source to enable you to do that). Then use your MSVC6 to create the extension. 4. Get and use MinGW and pyMinGW[2] Regards, Khalid [1] Check to see if your archiever tool is working, or get the source from CVS. [2] pyMinGW: http://jove.prohosting.com/iwave/ipython/pyMinGW.html -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: it would be quite useful for debuging porposes How does goto help you to remove bugs? I can certainly see how it helps you put them in in the first place... -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: (Python newbie) Using XP-SP2/MSVC6: No Python24_d.lib, winzip barfs on Python-2.4.1.tar, cannot download bzip2
Thanks Jaime, I'm making gradual progress and am finding it quite satisfying. Resorted to tracing Python in MSVC6 to see what it was trying to IMPORT, which is a bit heavy but thank heavens for the sources. Had not thouight of adapting SWIG, and will think about it when I have a clearer view of what I am doing (rather deeply embedded at present, trying to get one success). I had not spotted SWIG's wrapper round a wrapper (Module.py imports _Module.pyd) but it's reasonable except they go into different directories. And there's the _d too, of course :-( Many thanks for your help, Bill Jaime Wyant [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I fight the python24_d.lib problem with swig daily. The way I got around it was to modify swig's python configuration module. Mine was located at /lib/swig1.3/python/python.swg (I'm using cygwin) At the top, I changed #include python.h to #ifdef _DEBUG #undef _DEBUG #include python.h #define _DEBUG #else #include python.h #endif Somewhere in the includes, python uses a pragma telling the MSVC compiler which library to link the object files against. Because you're building a _DEBUG build, you magically get the python24_d.lib library. hth, jw On 4/18/05, Bill Davy [EMAIL PROTECTED] wrote: I downlaoded and installed http://www.python.org/ftp/python/2.4.1/python-2.4.1.msi I'm trying to build an extension using SWIG 1.3.24 and the linker needs python24_d.lib (I do not have the DLL either). I've not found it in any of the downloads. So I tried to download the source to build it myself. Of http://www.python.org/ftp/python/2.4.1/Python-2.4.1.tar.bz2 and http://www.python.org/ftp/python/2.4.1/Python-2.4.1.tgz, WinZip (9.0 SR1) just says Error reading header after processing 0 entries. Additionally, I've had no joy downloading the unzipper (ftp://sources.redhat.com/pub/bzip2/v102/bzip2-102-x86-win32.exe) from the site cited for the unzipper (http://sources.redhat.com/bzip2/). It flashed up a black console window momentarily. Oh, this is so frustrating! :-( Can anyone point me in the right direction? And then I can get to grips with my work. tia Bill -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Raymond Hettinger wrote: to seeing code like: for(i=0 ; in; i++) a[i]=f(i); In contrast, a BASIC programmer may be used to FOR I = 1 to N: a[I]=f(I); NEXT. Afaik, at least BBC BASIC uses zero based arrays :-) Maybe ZX Spectrum Basic too (too long ago to remember). -- John MexIT: http://johnbokma.com/mexit/ personal page: http://johnbokma.com/ Experienced programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Mage wrote: praba kar wrote: Dear All, In Python what is equivalent to goto statement You shouldn't use goto in high-level languages. Nonsense -- John MexIT: http://johnbokma.com/mexit/ personal page: http://johnbokma.com/ Experienced programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
John Bokma wrote: Mage wrote: praba kar wrote: Dear All, In Python what is equivalent to goto statement You shouldn't use goto in high-level languages. Nonsense Thank you! Above all your claim is well justified. These brilliant arguments you have put forth really explain in a magnificent way why goto is a sane addition to any HLL. Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Simon Brunning wrote: On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: it would be quite useful for debuging porposes How does goto help you to remove bugs? I can certainly see how it helps you put them in in the first place... if you need to comment a couple of code (and then uncomment ), what are you doing then? -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
[EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. Given another slice like mystring[2:4], you know instantly by looking at the slice indices that this contains 4-2 = 2 characters from the original string. If the last index were included in the slice, you'd have to remember to add 1 to get the number of characters in the sliced string. It all makes perfect sense when you look at it this way! Nick -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Maxim Kasimov wrote: Simon Brunning wrote: On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: it would be quite useful for debuging porposes How does goto help you to remove bugs? I can certainly see how it helps you put them in in the first place... if you need to comment a couple of code (and then uncomment ), what are you doing then? Use comments? -- 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: goto statement
Robert Kern wrote: Maxim Kasimov wrote: Simon Brunning wrote: On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: it would be quite useful for debuging porposes How does goto help you to remove bugs? I can certainly see how it helps you put them in in the first place... if you need to comment a couple of code (and then uncomment ), what are you doing then? Use comments? WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: trying to understand unicode
On 20 Apr 2005 10:58:35 GMT, F. Petitjean [EMAIL PROTECTED] wrote: Python has a very good support of unicode, utf8, encodings ... But I have some difficulties with the concepts and the vocabulary. You're not alone there. But I don't expect the docs for the Python implementation of Unicode to explain the concepts and vocabulary of Unicode. That's the job of the Unicode consortium, and they do a not-unreasonable job of it; see www.unicode.org and in particular http://www.unicode.org/Public/UNIDATA/UCD.html explains all the things that the Python unicodedata module is implementing. The documentation is not bad, but for example in reading http://docs.python.org/lib/module-unicodedata.html I had a long time to figure out what unicodedata.digit(unichr) would mean, a simple example is badly lacking. So I wrote the following script : [snip] I think that such code snippets should be included in the documentation or in a Wiki. Any effort should be directed (IMESHO) towards (a) keeping the URL in the Python documentation up-to-date [it's not] (b) using the *LATEST* version of the ucd file when each version of Python is released [still stuck on 3.2.0 when the current version available from Unicode.org is 4.1.0] [Exit, pursued by a bear.] [Noises off.] OK OK don't hit me, Martin, how about instructions on how to DIY, then? Cheers, John -- http://mail.python.org/mailman/listinfo/python-list
Re: XML parsing per record
Willem Ligtenberg wrote:
Willem Ligtenberg [EMAIL PROTECTED] wrote:
I want to parse a very large (2.4 gig) XML file (bioinformatics
ofcourse :)) But I have no clue how to do that. Most things I see read
the entire xml file at once. That isn't going to work here ofcourse.
So I would like to parse a XML file one record at a time and then be
able to store the information in another object. How should I do
that?
The XML file I need to parse contains information about genes.
So the first element is a gene and then there are a lot sub-elements with
sub-elements. I only need some of the informtion and want to store it in
my an object called gene. Lateron this information will be printed into a
file, which in it's turn will be fed into some other program.
This is an example of the XML
?xml version=1.0?
!DOCTYPE Entrezgene-Set PUBLIC -//NCBI//NCBI Entrezgene/EN
NCBI_Entrezgene.dtd
Entrezgene-Set
Entrezgene
snip
/Entrezgene
/Entrezgene-Set
This should get you started with cElementTree:
import cElementTree as ElementTree
source = 'Entrezgene.xml'
for event, elem in ElementTree.iterparse(source):
if elem.tag == 'Entrezgene':
# Process the Entrezgene element
geneid =
elem.findtext('Entrezgene_track-info/Gene-track/Gene-track_geneid')
print 'Gene id', geneid
# Throw away the element, we're done with it
elem.clear()
Kent
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Re: goto statement
Maxim Kasimov wrote: Robert Kern wrote: Maxim Kasimov wrote: Simon Brunning wrote: On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: it would be quite useful for debuging porposes How does goto help you to remove bugs? I can certainly see how it helps you put them in in the first place... if you need to comment a couple of code (and then uncomment ), what are you doing then? Use comments? WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows Use multi-line string literals. ''' This whole 'code' is commented out, and you can use every type of quote except three singles. ''' Or, if you really like the spirit of goto, use if 0:. Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Maxim Kasimov wrote: WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows There are editors that can comment and uncomment blocks. In worst case you can use to comment blocks (not elegant but works). Mage -- http://mail.python.org/mailman/listinfo/python-list
RE: goto statement
On 4/20/05, praba kar [EMAIL PROTECTED] wrote: In Python what is equivalent to goto statement An old user-friendly cartoon that might be relevant: http://ars.userfriendly.org/cartoons/?id=2506 Have fun :-) Sander -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows Get a decent text editor. -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
+1 Michel Claveau -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Hallchen! Maxim Kasimov [EMAIL PROTECTED] writes: [...] WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows Then just use a good editor. Tsch, Torsten. -- Torsten Bronger, aquisgrana, europa vetus -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Hallchen! [EMAIL PROTECTED] (Nick Efford) writes: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. [...] It all makes perfect sense when you look at it this way! Well, also in my experience every variant has its warts. You'll never avoid the i+1 or i-1 expressions in your indices or loops (or your mind ;). It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. But most programmers are used to do it the Python (and most other languages) way, so this opportunity has been missed for good. Tsch, Torsten. -- Torsten Bronger, aquisgrana, europa vetus -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Debugger with source code tracking ability
I haven't tried the customizations listed at the site below. If it works, let me know. http://page.sourceforge.net/tricks.html jw On 19 Apr 2005 19:45:05 -0700, Tran Tuan Anh [EMAIL PROTECTED] wrote: Hi all, I am new to Python and desperated to look for a good Python debugger. I mean a debugger with source coding tracking. For C/C++, emacs and gud offers execellent development env. The source code tracking is extremely useful for recursive functions. I have spent time Googling but not found anything near. Thanks! Tuan-Anh -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
exception handling
Hello,
def error_msg(msg):
sys.exit(msg)
try:
do_something()
if value != my_wish:
error_msg('Invalid input')
except:
print Fatal IO or Network error
This doesn't work because sys.exit raises an exception.
I know that I can define exception types after except, but there might
be many. Also I know I can write:
except:
if str(sys.exc_info()[0]) == 'exceptions.SystemExit':
raise
But honestly I would like simething like that:
except (!SystemExit):
Is this possible somehow?
Mage
--
http://mail.python.org/mailman/listinfo/python-list
Re: building a small calculator
I get the following error message when using the command sys.exit(). name 'sys' is not defined. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python instances
[EMAIL PROTECTED] wrote:
Guess i shouldn't think of the __init__(self) function as a constructor
then.
No, that's not it. You shouldn't think of variables defined outside of a
method as instance variables.
In Java for example you can write something like
public class MyClass {
private List list = new ArrayList();
public void add(Object x) {
list.add(x);
}
}
In this case list is a member variable of MyClass instances; 'this' is implicit
in Java.
In Python, if you write something that looks similar, the meaning is different:
class MyClass:
list = []
def add(self, x):
self.list.append(x)
In this case, list is an attribute of the class. The Java equivalent is a static attribute. In
Python, instance attributes have to be explicitly specified using 'self'. So instance attributes
have to be bound in an instance method (where 'self' is available):
class MyClass:
def __init__(self):
self.list = []
def add(self, x):
self.list.append(x)
Kent
--
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Re: building a small calculator
On 20 Apr 2005 05:31:15 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I get the following error message when using the command sys.exit(). name 'sys' is not defined. You really are new at this, aren't you? ;-) You need to import the sys module before you use it. Put this at the top of your script: import sys I'd also suggest that you have a run through the tutorial - http://docs.python.org/tut/. It's time well spent. If you don't get on with that, there's another couple of tutorials available aimed directly at those new to programming - http://www.livewires.org.uk/python/ and http://www.ibiblio.org/obp/thinkCSpy/. Lastly, although neophytes are more than welcome here, you might find the tutor mailing list a good place to ask questions in the early days of your Python experience. You'll find it here - http://mail.python.org/mailman/listinfo/tutor. -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: building a small calculator
Sorry. This is my first day using Python. Is there an equivelent to the goto command? I want to find some way to take the user back to the main menu. -- http://mail.python.org/mailman/listinfo/python-list
Redhat 9, Python 2.4.1, CGIHTTPServer problem
I cannot get a simple CGI-script to work with this combination : Redhat 9 Linux Both Python 2.41. and ActiveState Python 2.4.1 either as an Apache 2 cgi-script or using CGIHTTPServer. The same script works fine on Redhat 7.3. The script fails at 230 in CGIHTTPServer : osexecve(scriptfile,args.os.environ) the error message being OSError: [Errno 2] No such file or directory Can anyone through any light on this problem ?. I have seen a few references to problems in this area, but nothing that is helpful in solving the problem. Bill -- http://mail.python.org/mailman/listinfo/python-list
Re: building a small calculator
On 20 Apr 2005 05:41:37 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Sorry. This is my first day using Python. Nothing to apologise for. We were all new to Python once. Is there an equivelent to the goto command? I want to find some way to take the user back to the main menu. Funny you should mention that... http://groups-beta.google.com/group/comp.lang.python/browse_thread/thread/832906c6122dc137/f4cca2f994881220#f4cca2f994881220 -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing to stdout and a log file
Mike wrote: I should've mentioned I want StdoutLog to subclass the 'file' type because I need all the file attributes available. You might use a surrogate pattern. Here's one I use for this kind of situation, where I want to subclass but that can't be done for some reason. class SurrogateNotInitedError(exceptions.AttributeError): pass class Surrogate(object): def __init__(self, data): self._data = data def __getattr__(self, name): if name == _data: raise SurrogateNotInitedError, name else: try: return getattr(self._data, name) except SurrogateNotInitedError: raise SurrogateNotInitedError, name I'll leave it as an exercise to the reader to make this work when self._data is actually a list of objects instead of a single object. You'll obviously need special logic for different methods, like write(), since for some of them you will want to call every object in self._data, and others only a single object. -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
On Wednesday 20 April 2005 01:36 am, Raymond Hettinger wrote: [EMAIL PROTECTED] Many people I know ask why Python does slicing the way it does. [...] Python's way has some useful properties: [...] OTOH, it has some aspects that bite: [...] I suspect that whether it feels natural depends on your previous background and whether you're working in an environment with arrays indexed from one or from zero. For instance, C programmers are used to seeing code like: for(i=0 ; in; i++) a[i]=f(i); In contrast, a BASIC programmer may be used to FOR I = 1 to N: a[I]=f(I); NEXT.Hence, the C coders may find Python's a[:n] to be more natural than BASIC programmers. Well, I learned Basic, Fortran, C, Python --- more or less. And I first found Python's syntax confusing as it didn't follow the same rules as any of the previous ones. However, I used to make off by one errors all the time in both C and Fortran, whereas I hardly ever make them in Python. So I like Python's slicing because it bites *less* than intervals in C or Fortran. Cheers, Terry -- Terry Hancock ( hancock at anansispaceworks.com ) Anansi Spaceworks http://www.anansispaceworks.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Op 2005-04-20, Torsten Bronger schreef [EMAIL PROTECTED]: Hallöchen! [EMAIL PROTECTED] (Nick Efford) writes: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. [...] It all makes perfect sense when you look at it this way! Well, also in my experience every variant has its warts. You'll never avoid the i+1 or i-1 expressions in your indices or loops (or your mind ;). It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
praba kar wrote: In Python what is equivalent to goto statement http://groups-beta.google.com/group/comp.lang.python/msg/98264a0daa007c46 -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: Behaviour of str.split
Bengt Richter wrote:
On Wed, 20 Apr 2005 10:55:18 +0200, David Fraser [EMAIL PROTECTED] wrote:
Greg Ewing wrote:
Will McGugan wrote:
Hi,
I'm curious about the behaviour of the str.split() when applied to
empty strings.
.split() returns an empty list, however..
.split(*) returns a list containing one empty string.
Both of these make sense as limiting cases.
Consider
a b c.split()
['a', 'b', 'c']
a b.split()
['a', 'b']
a.split()
['a']
.split()
[]
and
**.split(*)
['', '', '']
*.split(*)
['', '']
.split(*)
['']
The split() method is really doing two somewhat different things
depending on whether it is given an argument, and the end-cases
come out differently.
You don't really explain *why* they make sense as limiting cases, as
your examples are quite different.
Consider
a*b*c.split(*)
['a', 'b', 'c']
a*b.split(*)
['a', 'b']
a.split(*)
['a']
.split(*)
['']
Now how is this logical when compared with split() above?
The trouble is that s.split(arg) and s.split() are two different functions.
The first is 1:1 and reversible like arg.join(s.split(arg))==s
The second is not 1:1 nor reversible: 'various whitespace'.join(s.split())
== s ?? Not usually.
I think you can do it with the equivalent whitespace regex, preserving the
splitout whitespace
substrings and ''.joining those back with the others, but not with split().
I.e.,
def splitjoin(s, splitter=None):
... return (splitter is None and 'whitespace' or
splitter).join(s.split(splitter))
...
splitjoin('a*b*c', '*')
'a*b*c'
splitjoin('a*b', '*')
'a*b'
splitjoin('a', '*')
'a'
splitjoin('', '*')
''
splitjoin('a bc')
'awhitespacebwhitespacec'
splitjoin('a b')
'awhitespaceb'
splitjoin(' b')
'b'
splitjoin('')
''
splitjoin('*','*')
'*'
Note why that works:
'*'.split('*')
['', '', '', '', '', '']
'*a'.split('*')
['', 'a']
'a*'.split('*')
['a', '']
splitjoin('*a','*')
'*a'
splitjoin('a*','*')
'a*'
Thanks, this makes sense.
So ideally if we weren't dealing with backward compatibility these
functions might have different names... split (with arg) and
spacesplit (without arg)
In fact it would be nice to allow an argument to spacesplit specifying
the characters regarded as 'space'
But all not worth breaking current code :-)
David
--
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Re: exception handling
Mage wrote:
def error_msg(msg):
sys.exit(msg)
try:
do_something()
if value != my_wish:
error_msg('Invalid input')
except:
print Fatal IO or Network error
This doesn't work because sys.exit raises an exception.
I know that I can define exception types after except, but there might
be many. Also I know I can write:
except:
if str(sys.exc_info()[0]) == 'exceptions.SystemExit':
raise
But honestly I would like simething like that:
except (!SystemExit):
Is this possible somehow?
try:
# may raise any exception
except SystemExit:
raise # propagate SystemExit (and subclasses)
except:
# handle everything else
Peter
--
http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Use multi-line string literals. ''' it will not help if there is another ''' or/and inside of code block This whole 'code' is commented out, and you can use every type of quote except three singles. ''' Or, if you really like the spirit of goto, use if 0:. ... and add tabs to each string Reinhold -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Raymond Hettinger [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] Many people I know ask why Python does slicing the way it does. Python's way has some useful properties: * s == s[:i] + s[i:] * len(s[i:j]) == j-i # if s is long enough The latter being particularly helpful when i = 0 -- the first n elements are s[:n] . (Similarly elegantly, although of no practical significance, s == s[0:len(s)] .) -- \S -- [EMAIL PROTECTED] -- http://www.chaos.org.uk/~sion/ ___ | Frankly I have no feelings towards penguins one way or the other \X/ |-- Arthur C. Clarke her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
On 20 Apr 2005 12:52:19 GMT, Antoon Pardon [EMAIL PROTECTED] wrote: Op 2005-04-20, Torsten Bronger schreef [EMAIL PROTECTED]: Hallöchen! [EMAIL PROTECTED] (Nick Efford) writes: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. [...] It all makes perfect sense when you look at it this way! Well, also in my experience every variant has its warts. You'll never avoid the i+1 or i-1 expressions in your indices or loops (or your mind ;). It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. -1. You can start arrays at 0 or 1 (and arbitrary bases? I don't recall) in VB, and it's an unmitigated disaster. It adds needless complexity. What our slicing system loses in elegance in a few cases, it more than makes up for in consistency throughout all programs. Peace Bill Mill bill.mill at gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Torsten Bronger wrote: Hallchen! Maxim Kasimov [EMAIL PROTECTED] writes: [...] WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows but what if i just can't to do this becouse i'm working thrue ssh, and have to use only installed editors (such as vi) -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Hallchen! Antoon Pardon [EMAIL PROTECTED] writes: Op 2005-04-20, Torsten Bronger schreef [EMAIL PROTECTED]: [...] It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. In HTBasic you have the choice between 0 and 1; there is a global source code directive for it. However, hardly anybody really wants to use HTBasic. Tsch, Torsten. -- Torsten Bronger, aquisgrana, europa vetus -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
On 4/20/05, Maxim Kasimov [EMAIL PROTECTED] wrote: Or, if you really like the spirit of goto, use if 0:. ... and add tabs to each string Get a decent text editor. What are you using? Notepad? -- Cheers, Simon B, [EMAIL PROTECTED], http://www.brunningonline.net/simon/blog/ -- http://mail.python.org/mailman/listinfo/python-list
Re: To decode the Subject =?iso-8859-2?Q?=... in email in python
Dan Polansky: When parsing messages using python's libraries email and mailbox, the subject is often encoded using some kind of = notation. Apparently, the encoding used in this notation is specified like =?iso-8859-2?Q?=... or =?iso-8859-2?B?=. Is there a python library function to decode such a subject, returning a unicode string? The use would be like human_readable = cool_library.decode_equals(message['Subject']) Here is some code from a front end to Mailman moderation pages: import email.Header hdr = email.Header.make_header(email.Header.decode_header(sub)) Neil -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Debugger with source code tracking ability
On 4/20/05, Jaime Wyant [EMAIL PROTECTED] wrote: I haven't tried the customizations listed at the site below. If it works, let me know. http://page.sourceforge.net/tricks.html jw On 19 Apr 2005 19:45:05 -0700, Tran Tuan Anh [EMAIL PROTECTED] wrote: Hi all, I am new to Python and desperated to look for a good Python debugger. I mean a debugger with source coding tracking. For C/C++, emacs and gud offers execellent development env. The source code tracking is extremely useful for recursive functions. You could take a look at Eclipse (http://eclipse.org/) in conjunction with pydev (http://pydev.sourceforge.net/). Or you could take a look at Komodo (http://www.activestate.com/Products/Komodo/) which is a commercial product with a trial version. Regards, R -- http://mail.python.org/mailman/listinfo/python-list
Re: exception handling
Mage [EMAIL PROTECTED] wrote:
Hello,
def error_msg(msg):
sys.exit(msg)
try:
do_something()
if value != my_wish:
error_msg('Invalid input')
except:
print Fatal IO or Network error
This doesn't work because sys.exit raises an exception.
Peter Otten posted a good way to do what you want, but I'm not convinced
that it's a good idea.
You're assuming that any exception you get will be a Fatal IO or Network
error. What if it's not? What if do_something() raises FutureWarning, or
KeyboardInterrupt, or AssertionError, or DeprecationWarning, or anything
else which has nothing to do with IO or networks? You would just end up
producing a misleading error message.
If you expect do_something() will throw certain exceptions, catch them
specifically. It's usually a mistake to catch everything. It's certainly
a mistake to catch everything and assume you know what it must be.
Try running the following code and see what happens:
import traceback
def do_something():
pass
try:
do_something()
if value != my_wish:
error_msg('Invalid input')
except:
print Fatal IO or Network error
print traceback.print_exc()
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Terry Hancock wrote: snip So I like Python's slicing because it bites *less* than intervals in C or Fortran. I disagree. Programming languages should not needlessly surprise people, and a newbie to Python probably expects that x[1:3] = [x[1],x[2],x[3]] . Array-oriented languages, such as Fortran 90/95, Matlab/Octave/Scilab, and S-Plus/R do not follow the Python convention, and I don't know of Fortran or R programmers who complain (don't follow Matlab enough to say). There are Python programmers, such as the OP and me, who don't like the Python convention. What languages besides Python use the Python slicing convention? Along the same lines, I think the REQUIREMENT that x[0] rather than x[1] be the first element of list x is a mistake. At least the programmer should have a choice, as in Fortran or VBA. In C starting at 0 may be justified because of the connection between array subscripting and pointer arithmetic, but Python is a higher-level language where such considerations are less relevant. -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Antoon Pardon [EMAIL PROTECTED] wrote: Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. Argggh. Having two (or more!) ways to do it, would mean that every time I read somebody else's code, I would have to figure out which flavor they are using before I could understand what their code meant. That would be evil. What would actually be cool is if Python were to support the normal math notation for open or closed intervals. Any of the following would make sense: foo = bar (1, 2) foo = bar (1, 2] foo = bar [1, 2) foo = bar [1, 2] That would certainly solve this particular problem, but the cost to the rest of the language syntax would be rather high :-) -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Op 2005-04-20, Bill Mill schreef [EMAIL PROTECTED]: On 20 Apr 2005 12:52:19 GMT, Antoon Pardon [EMAIL PROTECTED] wrote: Op 2005-04-20, Torsten Bronger schreef [EMAIL PROTECTED]: Hallöchen! [EMAIL PROTECTED] (Nick Efford) writes: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. [...] It all makes perfect sense when you look at it this way! Well, also in my experience every variant has its warts. You'll never avoid the i+1 or i-1 expressions in your indices or loops (or your mind ;). It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. -1. You can start arrays at 0 or 1 (and arbitrary bases? I don't recall) in VB, and it's an unmitigated disaster. It adds needless complexity. Complexity that is now put on the programmers shoulders. If I have a table with indexes going from -13 to +7, I have to add the offset myself if I want to use a list for that. What our slicing system loses in elegance in a few cases, it more than makes up for in consistency throughout all programs. You write this af if other solutions can't be consistent. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Maxim Kasimov wrote: Torsten Bronger wrote: Hallchen! Maxim Kasimov [EMAIL PROTECTED] writes: WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows but what if i just can't to do this becouse i'm working thrue ssh, and have to use only installed editors (such as vi) Surely you use more than one-character indents? If that's so, you can just insert the if 0: using, say, two characters indentation instead of the usual four. Then the following four-character-indented code is removed. Alternatively, use ''' and ''' surrounding the code block and it will be ignored. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: XML-RPC -- send file
codecraig stefan: i added, return 1 to my sendFile method on the server...took codecraig care of the error, thanks. Yes, by default XML-RPC doesn't support objects like Python's None. As the error message indicated you have to enable allow_none to permit transmission of None. Skip -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Op 2005-04-20, Roy Smith schreef [EMAIL PROTECTED]: Antoon Pardon [EMAIL PROTECTED] wrote: Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. Argggh. Having two (or more!) ways to do it, would mean that every time I read somebody else's code, I would have to figure out which flavor they are using before I could understand what their code meant. That would be evil. This is nonsens. table[i] = j, just associates value j with key i. That is the same independend from whether the keys can start from 0 or some other value. Do you also consider it more ways because the keys can end in different values? -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Peter Hansen wrote: Maxim Kasimov wrote: Torsten Bronger wrote: Hallchen! Maxim Kasimov [EMAIL PROTECTED] writes: WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows but what if i just can't to do this becouse i'm working thrue ssh, and have to use only installed editors (such as vi) Surely you use more than one-character indents? If that's so, you can just insert the if 0: using, say, two characters indentation instead of the usual four. Then the following four-character-indented code is removed. Alternatively, use ''' and ''' surrounding the code block and it will be ignored. f..., i don't requesting that goto was available in next versions of python, but i'm saying if it will be so, it will be easy and quickly _debug_ some skripts, _not only_ for commenting -- Best regards, Maxim Kasimov mailto: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: How to run Python in Windows w/o popping a DOS box?
Python.exe starts up a windows console which gives you things stdin, stderr, and stdout from the C runtime. Be warned that you do not have those things with the consoleless(?) pythonw.exe, stuff which MS intends for gui applications. It reminds me of select() on windows only working halfway (just w/sockets) because of the history of how all this got added to windows. A lot of half-way stuff. john -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
On 20 Apr 2005 13:39:42 GMT, Antoon Pardon [EMAIL PROTECTED] wrote: Op 2005-04-20, Bill Mill schreef [EMAIL PROTECTED]: On 20 Apr 2005 12:52:19 GMT, Antoon Pardon [EMAIL PROTECTED] wrote: Op 2005-04-20, Torsten Bronger schreef [EMAIL PROTECTED]: Hallöchen! [EMAIL PROTECTED] (Nick Efford) writes: [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Many people I know ask why Python does slicing the way it does. Can anyone /please/ give me a good defense/justification??? I'm referring to why mystring[:4] gives me elements 0, 1, 2 and 3 but *NOT* mystring[4] (5th element). mystring[:4] can be read as the first four characters of mystring. If it included mystring[4], you'd have to read it as the first five characters of mystring, which wouldn't match the appearance of '4' in the slice. [...] It all makes perfect sense when you look at it this way! Well, also in my experience every variant has its warts. You'll never avoid the i+1 or i-1 expressions in your indices or loops (or your mind ;). It's interesting to muse about a language that starts at 1 for all arrays and strings, as some more or less obsolete languages do. I think this is more intuitive, since most people (including mathematicians) start counting at 1. The reason for starting at 0 is easier memory address calculation, so nothing for really high level languages. Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. -1. You can start arrays at 0 or 1 (and arbitrary bases? I don't recall) in VB, and it's an unmitigated disaster. It adds needless complexity. Complexity that is now put on the programmers shoulders. If I have a table with indexes going from -13 to +7, I have to add the offset myself if I want to use a list for that. What our slicing system loses in elegance in a few cases, it more than makes up for in consistency throughout all programs. You write this af if other solutions can't be consistent. Propose one, and I won't write it off without thinking, but my bias is way against it from experience. Knowledge gets scattered across the program, unless you're defining the start index every time you use the list, which seems no better than adding an offset to me. Peace Bill Mill bill.mill at gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. Subclass from builtin list - and make the necessary adjustmenst yourself in an overloaded __getitem__. -- Regards, Diez B. Roggisch -- http://mail.python.org/mailman/listinfo/python-list
Re: Why Python does *SLICING* the way it does??
Antoon Pardon [EMAIL PROTECTED] wrote: Op 2005-04-20, Roy Smith schreef [EMAIL PROTECTED]: Antoon Pardon [EMAIL PROTECTED] wrote: Personnaly I would like to have the choice. Sometimes I prefer to start at 0, sometimes at 1 and other times at -13 or +7. Argggh. Having two (or more!) ways to do it, would mean that every time I read somebody else's code, I would have to figure out which flavor they are using before I could understand what their code meant. That would be evil. This is nonsens. table[i] = j, just associates value j with key i. That is the same independend from whether the keys can start from 0 or some other value. Do you also consider it more ways because the keys can end in different values? There are certainly many examples where the specific value of the first key makes no difference. A good example would be for element in myList: print element On the other hand, what output does myList = [spam, eggs, bacon] print myList[1] produce? In a language where some lists start with 0 and some start with 1, I don't have enough information just by looking at the above code. -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Maxim Kasimov wrote: Use multi-line string literals. ''' it will not help if there is another ''' or/and inside of code block Yes, but how often do you use them? And aren't you consistent in the choice of your quotes? This whole 'code' is commented out, and you can use every type of quote except three singles. ''' Or, if you really like the spirit of goto, use if 0:. ... and add tabs to each string Yes. Where's the problem? M-x indent-region-ly yours, Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
Maxim Kasimov wrote: f..., i don't requesting that goto was available in next versions of python, but i'm saying if it will be so, it will be easy and quickly _debug_ some skripts, _not only_ for commenting If you want, you can always use the goto module. Reinhold, no, I will not tell you where to find it -- http://mail.python.org/mailman/listinfo/python-list
Re: Python SSL Socket issue
Try con.connect() before the first putrequest -adam -- http://mail.python.org/mailman/listinfo/python-list
Re: Redhat 9, Python 2.4.1, CGIHTTPServer problem
It might not be the script, but might be the environment. I've been burned by something similar in the past when I had my CGI script in my home dir (default +r) and didnt have the permissions correct on the dir. Not only does the script have to be +r +x, but the dir it is in has to be as well for the apache user. -adam -- http://mail.python.org/mailman/listinfo/python-list
Re: goto statement
On Wed, 20 Apr 2005 14:58:35 +0300, rumours say that Maxim Kasimov [EMAIL PROTECTED] might have written: if you need to comment a couple of code (and then uncomment ), what are you doing then? Use comments? WOW, just greate! ... but i'd like to relax at some more interesting way than to comment each of rows What editor exactly are you using that can't un/indent and un/comment a block of lines? Obviously, neither vi, nor emacs, nor idle. -- TZOTZIOY, I speak England very best. Be strict when sending and tolerant when receiving. (from RFC1958) I really should keep that in mind when talking with people, actually... -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie question
In article [EMAIL PROTECTED], Tiziano Bettio [EMAIL PROTECTED] wrote: . . . If u want to achieve high performance you'd rather use c++ and directly access libs like nvidias cg, ms directx or opengl... . . . Yes. Well, maybe. Python-coded programs, even graphically-intense games, *can* exhibit good performance, and there are numerous anecdotes about applications LOSING speed on conversion to C++ from Python. Moreover, there's no inherent conflict between C++ and Python; some successful applications use both. My summary: it's a subtler matter than, for performance, abandon Python on favor of C++. I think you know that, but I want to make it explicit for less-experienced readers. -- http://mail.python.org/mailman/listinfo/python-list
random number between 0 and 20
How can I generate a random number between 0 - 20 and store the number in nrrandom? -- http://mail.python.org/mailman/listinfo/python-list
