automatically assigning names to indexes
I know its been done before, but I'm hacking away on a simple Vector class. class Vector(tuple): def __add__(self, b): return Vector([x+y for x,y in zip(self, b)]) def __sub__(self, b): return Vector([x-y for x,y in zip(self, b)]) def __div__(self, b): return Vector([x/b for x in self]) def __mul__(self, b): return Vector([x*b for x in self]) I like it, because it is simple, and can work with vectors of any size... However, I'd like to add attribute access (magically), so I can do this: v = Vector((1,2,3)) print v.x print v.y print v.z as well as: print v[0] print v[1] print v[2] Has anyone got any ideas on how this might be done? Sw. -- http://mail.python.org/mailman/listinfo/python-list
Re: __eq__ on a dict
Replying to myself... how sad.
On Tue, 12 Jul 2005 15:41:46 +1000, Steven D'Aprano wrote:
That wasn't clear from his post at all. If he had explained what he
wanted, I wouldn't have wasted my time explaining what he already knew.
On reading it, that came across more snarky than I intended. Sorry.
Asking the right question helps. But not in this case, because comparison
of objects is ... confusing. There doesn't seem to be any definitive
answer to the question, not that I have been able to find, although plenty
of hints.
My first thought was the comparisons between dicts is implemented as
comparisons between their items, ie cmp(dictA, dictB) is turned into
cmp(dictA.items(), dictB.items()). But that doesn't seem to be the case:
However, I wasn't completely insane, since I came across this tidbit:
http://python.active-venture.com/ref/comparisons.html
Mappings (dictionaries) compare equal if and only if their sorted (key,
value) lists compare equal. Outcomes other than equality are resolved
consistently, but are not otherwise defined.
with a footnote leading to this comment:
Earlier versions of Python used lexicographic comparison of the sorted
(key, value) lists, but this was very expensive for the common case of
comparing for equality.
I also suggested:
My second thought was that comparison is implemented by first comparing
keys, then values, ie cmp(dictA, dictB)
[snip]
I don't think I can prove it though.
I certainly can't prove it, since my example pseudo-code fails even on the
example I used earlier. Sigh.
In summary:
Equality of dicts is guaranteed. Two dicts are equal if and only if their
keys:value pairs are equal. Other orderings between dicts are calculated
consistently but not in any documented way.
One gotcha is that some dicts are unordered:
py {1:1j} {1:2j}
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: cannot compare complex numbers using , =, , =
but even that is special-cased up to the wazzoo:
py {1:1j} {1:1j}
False
--
Steven.
--
http://mail.python.org/mailman/listinfo/python-list
Web App like Google
Hello there,
I need some thoughts about a web application that i am dreaming
and drooling about in python. I want a search page to look exactly like
Google. But when i press the search button, it should search a database
in an rdbms like Oracle and provide results.
For example, if my keywords are all customers with names
starting with 'God' it should somehow search table CUSTOMER , with
following query :
SELECT CUSTNAME FROM CUSTOMER WHERE CUSTNAME LIKE 'God%'
So we basically need is a good python parser module which parses the
keywords into an sql or sqls and list the results. I can look in the
keywords for table and column synonyms and map it into
table and column names and create sql but it's not a foolproof idea as
we all know that english is a very vague language. The above idea wil
fail , if i can't identify table,column names
,operators and values in their logical orders so as to create a
syntactically correct sql. If there are more tables involved, i should
also think of joining tables (inner,outer,equi joins).
All I want is some enlightening thoughts from the python hackers(i mean
programmers) out there.Plz polish your grey cells and let me know your
thoughts.
# this is my basic and foolish keywordparser
# the object db provides the table as well as column names
# as u can see it may or may not work even for a single table
class KeyWordParser(object):
def __init__(self,keywords,db):
self.keywords = keywords.upper().split()
self.db = db
self.tables = []
self.columns = []
def parse2sql(self):
for word in self.keywords:
if word in self.db.tables():
self.tables.append(word)
for word in self.keywords:
for table in self.tables:
for column in self.db.columns(table):
if column == word:
self.columns.append(column)
sql = 'SELECT %s FROM %s' % (','.join(self.columns) or
'*',','.join(self.tables))
return sql
--
http://mail.python.org/mailman/listinfo/python-list
Replacing last comma in 'C1, C2, C3' with 'and' so that it reads 'C1, C2 and C3'
Hi, I have a string such as 'C1, C2, C3'. Without assuming that each bit of text is of fixed size, what is the easiest way to change this list so that it reads: 'C1, C2 and C3' regardless of the length of the string. Regards and sorry for the newbie question, Ric -- http://mail.python.org/mailman/listinfo/python-list
Re: __autoinit__
--- Mike Meyer [EMAIL PROTECTED] wrote: Remember that what we're suggesting is just syntactic sugar. BTW: That's true for all high-level language constructs. You could do everything in machine language. A good language is the sum of lots of syntactic sugar... selected with taste. :) You can abuse things the same way by writing: class grouping: def __init__(self, self.x, u_y, self.z): u.y = u_y del u_y pass Why is this acceptable, but your usage not? Hmmm. Maybe this is where I'd draw the line: Effects of code in the *signature* must be restricted to self and locals(). self is special here because the whole purpose of the constructor is to initialize self; otherwise you'd use a plain function. Therefore it seems more than natural to provide special support. self (or whatever people prefer as a name for the first argument of a bound function) *is* special. I think therefore it deserves special support. Yes, but is it special enough to justify adding a special case to another construct? In my mind that's determined by the usage patterns as they arise in practice. A high degree of redundancy is the worst enemy of good, readable code. The language/framework definitely should help out here in some way. I'm not sure I like the idea of allowing self.x yet. But if you're going to allow it, I don't think it should be restricted. If that's the price I have to pay for the feature I am all for it. :) However, I feel we will get into a lot of trouble with the purists. They will tell us that side-effects are generally vicious. The question is - how far are you really willing to carry this? What do you think of allowing arbitrary lvalues, with the assumption that the previous arguments are all defined (ala let*)? So you could do: class grouping: def __init__(self, x, x['abc']): pass mike I am not sure this fits into the given framework. E.g.: from cStringIO import StringIO import sys def show(data, file_object=sys.stdout): print file_object, data sys.stdout = StringIO() show(hello, world.) If you run this, you will see hello, world. on the screen. This means the right side of file_object=sys.stdout is evaluated when the Python code is parsed/compiled, not when it is executed. Cheers, Ralf __ Do you Yahoo!? Yahoo! Mail - You care about security. So do we. http://promotions.yahoo.com/new_mail -- http://mail.python.org/mailman/listinfo/python-list
Re: Replacing last comma in 'C1, C2, C3' with 'and' so that it reads 'C1, C2 and C3'
Ric Da Force wrote: I have a string such as 'C1, C2, C3'. Without assuming that each bit of text is of fixed size, what is the easiest way to change this list so that it reads: 'C1, C2 and C3' regardless of the length of the string. and.join(C1, C2, C3.rsplit(,, 1)) 'C1, C2 and C3' Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Replacing last comma in 'C1, C2, C3' with 'and' so that it reads 'C1, C2 and C3'
foo = C1, C2, C3 foo = foo.split(, ) # ['C1', 'C2', 'C3'] foo = , .join(foo[:-1]) + and + foo[-1] # just slicing and joining it you can always look for something here: http://docs.python.org/lib/lib.html and there: http://docs.python.org/ref/ if you want to know, what methods an object has, try this (i shortened the output a bit): foo = C1, C2, C3 dir(foo) ['__add__', '__doc__', ..., 'capitalize', 'center', 'count', 'decode','encode', 'endswith', 'expandtabs', 'find', 'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'replace', 'rfind', 'rindex', 'rjust', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill'] -- http://mail.python.org/mailman/listinfo/python-list
Re: Replacing last comma in 'C1, C2, C3' with 'and' so that it reads 'C1, C2 and C3'
Ric Da Force said unto the world upon 12/07/2005 02:43:
Hi,
I have a string such as 'C1, C2, C3'. Without assuming that each bit of
text is of fixed size, what is the easiest way to change this list so that
it reads:
'C1, C2 and C3' regardless of the length of the string.
Regards and sorry for the newbie question,
Ric
Hi Ric,
the rsplit method of strings should get you going:
data = the first bit, then the second, finally the third
chunks = data.rsplit(',', 1)
chunks
['the first bit, then the second', ' finally the third']
Best,
Brian vdB
--
http://mail.python.org/mailman/listinfo/python-list
Re: __eq__ on a dict
Hi Steven,
Thanks for digging into this.
Steven D'Aprano [EMAIL PROTECTED] writes:
Replying to myself... how sad.
On Tue, 12 Jul 2005 15:41:46 +1000, Steven D'Aprano wrote:
That wasn't clear from his post at all. If he had explained what he
wanted, I wouldn't have wasted my time explaining what he already knew.
On reading it, that came across more snarky than I intended. Sorry.
It's ok. I realize the OP did not make it crystal clear what he was
getting at in his post. It's easier when you are sitting in the same
office ;-).
However, I wasn't completely insane, since I came across this tidbit:
http://python.active-venture.com/ref/comparisons.html
Mappings (dictionaries) compare equal if and only if their sorted (key,
value) lists compare equal. Outcomes other than equality are resolved
consistently, but are not otherwise defined.
with a footnote leading to this comment:
Earlier versions of Python used lexicographic comparison of the sorted
(key, value) lists, but this was very expensive for the common case of
comparing for equality.
Ah, I missed that, thanks for the pointer. Seems information of
dictionary comparisons should also appear in the Library Reference
under Mapping Types.
I also suggested:
My second thought was that comparison is implemented by first comparing
keys, then values, ie cmp(dictA, dictB)
[snip]
I don't think I can prove it though.
Looking at the source code links Simon posted (thanks Simon!) it is
clear that, in the current version of CPython, dictionaries are
ordered first by length and only if the lengths are equal are the
keys and values examined.
Equality of dicts is guaranteed. Two dicts are equal if and only if their
keys:value pairs are equal. Other orderings between dicts are calculated
consistently but not in any documented way.
One gotcha is that some dicts are unordered:
py {1:1j} {1:2j}
Traceback (most recent call last):
File stdin, line 1, in ?
TypeError: cannot compare complex numbers using , =, , =
but even that is special-cased up to the wazzoo:
py {1:1j} {1:1j}
False
Hmm... not sure I like that!
--
Aaron Bingham
Senior Software Engineer
Cenix BioScience GmbH
--
http://mail.python.org/mailman/listinfo/python-list
Re: Replacing last comma in 'C1, C2, C3' with 'and' so that it reads 'C1, C2 and C3'
If that can help you... def replaceLastComma(s): i = s.rindex(,) return ' and'.join([s[:i], s[i+1:]]) I don't know of ot's better to do a: ' and'.join([s[:i], s[i+1:]]) Or: ''.join([s[:i], ' and', s[i+1:]]) Or: s[:i] + ' and' + s[i+1] Maybe the better solution is not in the list... Cyril On 7/12/05, Ric Da Force [EMAIL PROTECTED] wrote: Hi,I have a string such as 'C1, C2, C3'. Without assuming that each bit oftext is of fixed size, what is the easiest way to change this list so thatit reads:'C1, C2 and C3' regardless of the length of the string. Regards and sorry for the newbie question,Ric--http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: set and frozenset unit tests?
Jacob Page wrote: I have released interval-0.2.1 at http://members.cox.net/apoco/interval/. IntervalSet and FrozenIntervalSet objects are now (as far as I can tell) functionality equivalent to set and frozenset objects, except they can contain intervals as well as discrete values. Though I have my own unit tests for verifying this claim, I'd like to run my code through actual set and frozenset unit tests. Does any such code exist? Is it in pure Python? If so, where can it be obtained? Oh, and again, I'd really appreciate additional feedback on the module, especially related to design, if you've got any. My goal for this project is to make the classes built-in-data-type quality. Look at /usr/lib/python2.x/test/ (on unix platforms). Reinhold -- http://mail.python.org/mailman/listinfo/python-list
Re: automatically assigning names to indexes
class Vector(tuple):
... x = property(lambda self: self[0])
... y = property(lambda self: self[1])
... z = property(lambda self: self[2])
...
Vector(abc)
('a', 'b', 'c')
Vector(abc).z
'c'
Vector(abc)[2]
'c'
Aha! You have simultaneously proposed a neat solution, and shown me a
bug in my class! (It shouldn't accept strings)
Thanks.
Sw.
--
http://mail.python.org/mailman/listinfo/python-list
Search Replace with RegEx
Hi Pythonistas,
Here's my problem: I'm using a version of MOOX Firefox
(http://moox.ws/tech/mozilla/) that's been modified to run completely
from a USB Stick. It works fine, except when I install or uninstall an
extension, in which case I then have to physically edit the compreg.dat
file in my profile directory, replacing all instances of Absolute Path
links to relative ones. (And, yes, I have filed a Bugzilla report.)
For example, after installing a new extension, I change in compreg.dat
lines such as:
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{0538E3E3-7E9B-4d49-8831-A227C80A7AD3}\components\nsForecastfox.js,18590
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{c4dc572a-3295-40eb-b30f-b54aa4cdc4b7}\components\wml-service.js,111470502
to:
rel:nsForecastfox.js,18590
rel:wml-service.js,111470502
I started a Python script that searches compreg.dat and finds all the
lines that I need to edit. I just need some help using RegEx to search
and replace these lines (as in the examples above), so that I no longer
need to edit compreg.dat manually.
Here's the script that I started:
import os
import re
import fileinput
theRegEx = '.*abs:.*\.*.js.*'
p = re.compile(theRegEx, re.IGNORECASE)
fileToSearch = 'compreg.dat'
print File to perfrom search-and-replace on: + fileToSearch
print Using Regex: + theRegEx
print
if os.path.isfile( fileToSearch ):
tempFile = open( fileToSearch, 'r' )
for line in fileinput.input( fileToSearch ):
if (p.match(line)!=None):
print line
tempFile.close()
raw_input( '\n\nPress Enter to exit...' )
I'd be very glad to get a helping hand here ;)
Thanks,
Tom
--
http://mail.python.org/mailman/listinfo/python-list
Re: Managment of Python Libraries
Joseph Chase wrote: I am new to Python. In the past, I have noticed that I have spent a lot of time managing my C++ libraries. When my personal frameworks got large enough, and some moving around/refactoring was apparent, it was an absolute nightmare. As I embark on the wonderful language of Python, or there any object organizational tools that may help me to keep order? There's Bicycle Repair Man: http://bicyclerepair.sourceforge.net/ -- 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 come to grips with static methods
I've been doing a lot of reading about static methods in Python, and I'm not exactly sure what they are useful for or why they were introduced. Here is a typical description of them, this one from Guido: The new descriptor API makes it possible to add static methods and class methods. Static methods are easy to describe: they behave pretty much like static methods in C++ or Java. http://www.python.org/2.2.3/descrintro.html Great. So I have learn an entire new language to understand static methods. Perhaps not -- hence this cry for help. As near as I can see it, static methods are object methods that act just like functions. Er. I always thought that object methods *were* functions, except they had some runtime magic that passed the object itself as the first argument. From Guido's example: class C: ... def foo(x, y): ... print staticmethod, x, y ... foo = staticmethod(foo) ... C.foo(1, 2) staticmethod 1 2 c = C() c.foo(1, 2) staticmethod 1 2 So I compare with an ordinary class function, er, method: class D: ... def foo(self, x, y): ... print method, x, y ... D.foo(1, 2) Traceback (most recent call last): File stdin, line 1, in ? TypeError: unbound method foo() must be called with D instance as first argument (got int instance instead) Okay, that is to be expected. Actually, I expected an exception that I hadn't passed enough arguments (2 arguments when foo expects 3), but in hindsight it is obvious enough. First point of confusion. In the above exception, foo is called an unbound method. But type(D.foo) returns type 'instancemethod' even though foo is being access through the class, not an instance. And type(D().foo) returns the same. Can I assume that in Python unbound method is just another way of saying a method of a class that expects to be called via an instance? I next tried this: D.foo(D(), 1, 2) method 1 2 D().foo(1, 2) method 1 2 Clear as mud. An ordinary method called from an instance is the same as a static method called from anywhere, provided you don't -- or rather, can't -- try to access self from the static method. When would you use a static method instead of an ordinary method? It has been suggested that you might use it for functions that don't need to access self. But that doesn't seem very convincing to me, because there is already a perfectly good idiom for that: class E: ... def foo(): # returns calculated value ... return 1 ... foo = staticmethod(foo) ... def bar(self): ... return 1 # just ignore the value of self ... E.foo() 1 e = E() e.bar() 1 What are some usage cases for using Class.StaticMethod() instead of instance.method()? Everything I've read seems to just assume that the benefits of static methods are so obvious that they don't need explaining. Unfortunately, I haven't come from a background in OO and I'm easily confused, hence this post. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Should I use if or try (as a matter of speed)?
Thorsten Kampe [EMAIL PROTECTED] writes:
Speed considerations and benchmarking should come in after you wrote
the program. Premature optimisation is the root of all evil and
first make it work, then make it right, then make it fast (but only
if it's not already fast enough) - common quotes not only with Python
developers.
Just a minor note: regarding quote
first make it work, then make it right, then make it fast
Shouldn't one avoid doing it the wrong way from the very beginning? If you
make it just work the first time, you'll probably use the old code later on
because functionality is already there and temptatation to build on probably
relatively bad architecture can be too strong.
How about
First make it work (but avoid ad-hoc designs), then make it right, then make
it fast
Of course, such emphasis doesn't go well with classic idioms..
(yeah, programmer's block at the moment: I should clean up a 120+ -line
if-elif-elif-elif... else -block which tests a single variable and calls
different methods with variable number of parameters depending on the value of
the variable - guess I should apply command pattern or similar...)
--
# Edvard Majakari Software Engineer
# PGP PUBLIC KEY available Soli Deo Gloria!
$_ = '456476617264204d616a616b6172692c20612043687269737469616e20'; print
join('',map{chr hex}(split/(\w{2})/)),uc substr(crypt(60281449,'es'),2,4),\n;
--
http://mail.python.org/mailman/listinfo/python-list
Re: Trying to come to grips with static methods
Im my opinion, class method are used to store some functions related to a class in the scope of the class. For example, I often use static methods like that: class Foo: On 7/12/05, Steven D'Aprano [EMAIL PROTECTED] wrote: I've been doing a lot of reading about static methods in Python, and I'mnot exactly sure what they are useful for or why they were introduced.Here is a typical description of them, this one from Guido: The new descriptor API makes it possible to add static methods and classmethods. Static methods are easy to describe: they behave pretty much likestatic methods in C++ or Java. http://www.python.org/2.2.3/descrintro.htmlGreat. So I have learn an entire new language to understand staticmethods. Perhaps not -- hence this cry for help.As near as I can see it, static methods are object methods that act just like functions. Er. I always thought that object methods *were* functions,except they had some runtime magic that passed the object itself as thefirst argument.From Guido's example: class C: ... def foo(x, y):... print staticmethod, x, y... foo = staticmethod(foo)... C.foo(1, 2)staticmethod 1 2 c = C() c.foo(1, 2) staticmethod 1 2So I compare with an ordinary class function, er, method: class D:... def foo(self, x, y):... print method, x, y... D.foo (1, 2)Traceback (most recent call last):File stdin, line 1, in ?TypeError: unbound method foo() must be called with D instance as firstargument (got int instance instead)Okay, that is to be expected. Actually, I expected an exception that I hadn't passed enough arguments (2 arguments when foo expects 3), but inhindsight it is obvious enough.First point of confusion. In the above exception, foo is called an unboundmethod. But type(D.foo) returns type 'instancemethod' even though foo is being access through the class, not an instance. And type(D().foo) returnsthe same.Can I assume that in Python unbound method is just another way of sayinga method of a class that expects to be called via an instance? I next tried this: D.foo(D(), 1, 2)method 1 2 D().foo(1, 2)method 1 2Clear as mud. An ordinary method called from an instance is the same as astatic method called from anywhere, provided you don't -- or rather, can't -- try to access self from the static method.When would you use a static method instead of an ordinary method? It hasbeen suggested that you might use it for functions that don't need toaccess self. But that doesn't seem very convincing to me, because there is already a perfectly good idiom for that: class E:... def foo():# returns calculated value... return 1... foo = staticmethod(foo)... def bar(self):... return 1# just ignore the value of self ... E.foo()1 e = E() e.bar()1What are some usage cases for using Class.StaticMethod() instead ofinstance.method()? Everything I've read seems to just assume that the benefits of static methods are so obvious that they don't need explaining.Unfortunately, I haven't come from a background in OO and I'm easilyconfused, hence this post.--Steven.-- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Trying to come to grips with static methods
Steven D'Aprano wrote: I've been doing a lot of reading about static methods in Python, and I'm not exactly sure what they are useful for or why they were introduced. Here is a typical description of them, this one from Guido: The new descriptor API makes it possible to add static methods and class methods. Static methods are easy to describe: they behave pretty much like static methods in C++ or Java. http://www.python.org/2.2.3/descrintro.html Great. So I have learn an entire new language to understand static methods. Perhaps not -- hence this cry for help. As near as I can see it, static methods are object methods that act just like functions. Er. I always thought that object methods *were* functions, except they had some runtime magic that passed the object itself as the first argument. [snip] What are some usage cases for using Class.StaticMethod() instead of instance.method()? Everything I've read seems to just assume that the benefits of static methods are so obvious that they don't need explaining. Unfortunately, I haven't come from a background in OO and I'm easily confused, hence this post. staticmethods don't see a whole lot of use in Python. They see use in Java because everything has to be stuck in a class, even if they don't actually require an instance of the class to work. In Python, you usually just define a function. I think staticmethod was implemented along with classmethod primarily for completeness than anything else. OTOH, I do find myself using them occasionally to group such functions appropriately. I'll be writing a utility method that doesn't actually need an instance or the class to be passed in, so I make it a staticmethod. It *could* just as well be a module-level function, but sometimes it really belongs tucked in with the class. It could also be a regular method, but then I can't call it from the outside without actually having an instance which isn't actually needed. It could also be a classmethod, but since it doesn't actually need any information from the class to do its work, I find that the extra reminder of staticmethod helps my brain understand what it's doing. All told, I'd probably vote -0.5 on a builtin staticmethod if it came up today. -- 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: Trying to come to grips with static methods
(sorry, my fingers send the mail by there own ;-) Im my opinion, class method are used to store some functionalities (function) related to a class in the scope of the class. For example, I often use static methods like that: class Point: def __init__(self, x, y): self.x, self.y = x, y def fromXML(xmlText): x, y = functionToParseXMLUsingMinidomForExample(xmlText) return Point(x, y) fromXML = staticmethod(fromXML) Here, it is used to define some kind of second constructor... Note that class decorator can simplify the notation, but break the compatility with older Python... Cyril On 7/12/05, Steven D'Aprano [EMAIL PROTECTED] wrote: I've been doing a lot of reading about static methods in Python, and I'mnot exactly sure what they are useful for or why they were introduced.Here is a typical description of them, this one from Guido: The new descriptor API makes it possible to add static methods and classmethods. Static methods are easy to describe: they behave pretty much likestatic methods in C++ or Java. http://www.python.org/2.2.3/descrintro.htmlGreat. So I have learn an entire new language to understand staticmethods. Perhaps not -- hence this cry for help.As near as I can see it, static methods are object methods that act just like functions. Er. I always thought that object methods *were* functions,except they had some runtime magic that passed the object itself as thefirst argument.From Guido's example: class C: ... def foo(x, y):... print staticmethod, x, y... foo = staticmethod(foo)... C.foo(1, 2)staticmethod 1 2 c = C() c.foo(1, 2) staticmethod 1 2So I compare with an ordinary class function, er, method: class D:... def foo(self, x, y):... print method, x, y... D.foo (1, 2)Traceback (most recent call last):File stdin, line 1, in ?TypeError: unbound method foo() must be called with D instance as firstargument (got int instance instead)Okay, that is to be expected. Actually, I expected an exception that I hadn't passed enough arguments (2 arguments when foo expects 3), but inhindsight it is obvious enough.First point of confusion. In the above exception, foo is called an unboundmethod. But type(D.foo) returns type 'instancemethod' even though foo is being access through the class, not an instance. And type(D().foo) returnsthe same.Can I assume that in Python unbound method is just another way of sayinga method of a class that expects to be called via an instance? I next tried this: D.foo(D(), 1, 2)method 1 2 D().foo(1, 2)method 1 2Clear as mud. An ordinary method called from an instance is the same as astatic method called from anywhere, provided you don't -- or rather, can't -- try to access self from the static method.When would you use a static method instead of an ordinary method? It hasbeen suggested that you might use it for functions that don't need toaccess self. But that doesn't seem very convincing to me, because there is already a perfectly good idiom for that: class E:... def foo():# returns calculated value... return 1... foo = staticmethod(foo)... def bar(self):... return 1# just ignore the value of self ... E.foo()1 e = E() e.bar()1What are some usage cases for using Class.StaticMethod() instead ofinstance.method()? Everything I've read seems to just assume that the benefits of static methods are so obvious that they don't need explaining.Unfortunately, I haven't come from a background in OO and I'm easilyconfused, hence this post.--Steven.-- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
pychecker filtering
Hi, I'm trying to make a decent .pycheckrc for our project and have stumbled on a few issues. (the pychecker-list would have seemed like the appropriate place, but the S/N ratio seemed very low with all the spam) - for various reasons we decided to add an attribute to a module in the stdlib, lets say os.foo. Now, pychecker screams No module attribute (foo) found in a lot of places, which is not desirable. (Yes I know, don't do that, fix the original problem etc.. We probably will eventually, but for now, I just don't want to see those) I thought of doing something with the suppressions dict, but could not figure out how to use that in this particular case. Another thing, we have a lot of autogenerated files which contain a function _translateException which is basically a huge dictionary lookup. Here pychecker complains about too many lines, can I somehow suppress RandomNameWrapper.RandomName._translateException or failing that, all _translateException (manually including every name does not seem like fun..) /Simon -- http://mail.python.org/mailman/listinfo/python-list
Re: Trying to come to grips with static methods
Cyril Bazin wrote:
(sorry, my fingers send the mail by there own ;-)
Im my opinion, class method are used to store some functionalities
(function) related to a class in the scope of the class.
For example, I often use static methods like that:
class Point:
def __init__(self, x, y):
self.x, self.y = x, y
def fromXML(xmlText):
x, y = functionToParseXMLUsingMinidomForExample(xmlText)
return Point(x, y)
fromXML = staticmethod(fromXML)
Here, it is used to define some kind of second constructor...
Note that class decorator can simplify the notation, but break the
compatility with older Python...
Huh? classmethod was introduced with staticmethod, and in fact, this use
case is exactly what classmethods are for, not staticmethods.
In [2]: class Point(object): # -- note inheritance from object
...: def __init__(self, x, y):
...: self.x, self.y = x, y
...: def fromXML(cls, xmlText):
...: x, y = parseXML(xmlText)
...: return cls(x, y)
...: fromXML = classmethod(fromXML)
...:
In [3]: class NewPoint(Point):
...: pass
...:
In [4]: def parseXML(xmlText):
...: return 1, 4
...:
In [5]: p = NewPoint.fromXML('point x=1 y=4/point')
In [6]: isinstance(p, NewPoint)
Out[6]: True
--
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: Trying to come to grips with static methods
Ok, sorry, you are right Robert.
What about this one:
class Parser(object):
def toParser(p):
if type(p) == str:
if len(p) == 1:
return lit(p)
return txt(p)
return p
toParser = staticmethod(toParser)
This is meant to translate p to a parser if it's not one.
'lit' is a function that take a string of length 1 and return a parser of char.
'txt' is a function that take a string of any length and return a parser.
I hope it is a better example!
That one of the rare case I used static method in Python...
Cyril
On 7/12/05, Robert Kern [EMAIL PROTECTED] wrote:
Cyril Bazin wrote: (sorry, my fingers send the mail by there own ;-) Im my opinion, class method are used to store some functionalities (function) related to a class in the scope of the class.
For example, I often use static methods like that: class Point: def __init__(self, x, y): self.x, self.y = x, y def fromXML(xmlText): x, y = functionToParseXMLUsingMinidomForExample(xmlText)
return Point(x, y) fromXML = staticmethod(fromXML) Here, it is used to define some kind of second constructor... Note that class decorator can simplify the notation, but break the
compatility with older Python...Huh? classmethod was introduced with staticmethod, and in fact, this usecase is exactly what classmethods are for, not staticmethods.In [2]: class Point(object):# -- note inheritance from object
...: def __init__(self, x, y):...: self.x, self.y = x, y...: def fromXML(cls, xmlText):...: x, y = parseXML(xmlText)...: return cls(x, y)...: fromXML = classmethod(fromXML)
...:In [3]: class NewPoint(Point):...: pass...:In [4]: def parseXML(xmlText):...: return 1, 4...:In [5]: p = NewPoint.fromXML('point x=1 y=4/point')
In [6]: isinstance(p, NewPoint)Out[6]: True--Robert Kern[EMAIL PROTECTED]In the fields of hell where the grass grows highAre the graves of dreams allowed to die.
-- Richard Harter--http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
Sort files by date
Hi. I'm looking for some way to sort files by date. I'm usin glob module to list a directiry, but files are sorted by name. import glob path = ./ for ScannedFile in glob.glob(path): ... print ScannedFile I googled my problem, but did not find any solution, neither in this newsgroup. Can anyone help me ? Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Efficiency of using long integers to hold bitmaps
Raymond, Thanks for your answers, which even covered the question that I didn't ask but should have. code A Python list is not an array()\n * 100 /code :) Jeff Raymond Hettinger [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [Jeff Melvaine] I note that I can write expressions like 1 100 and the result is stored as a long integer, which means it is stored as an integer of arbitrary length. I may need to use a large number of these, and am interested to know whether the storage efficiency of long integers is in danger of breaking my code if I use too many. Would I do better to write a class that defines bitwise operations on arrays of integers, each integer being assumed to contain at most 32 bits? Both array() objects and long integers are equally space efficient. In contrast, a list of integers takes up a lot of space (the list is stored as an array of pointers to individual integer objects). Raymond -- http://mail.python.org/mailman/listinfo/python-list
Re: Sort files by date
fargo wrote:
I'm looking for some way to sort files by date.
you could do something like:
l = [(os.stat(i).st_mtime, i) for i in glob.glob('*')]
l.sort()
files = [i[1] for i in l]
Jeremy
--
Jeremy Sanders
http://www.jeremysanders.net/
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort files by date
Jeremy Sanders wrote:
you could do something like:
l = [(os.stat(i).st_mtime, i) for i in glob.glob('*')]
l.sort()
files = [i[1] for i in l]
Thank you for your help, this is excatly what I wasa looking for.
--
http://mail.python.org/mailman/listinfo/python-list
Creating anonymous functions using eval
I've been playing with a function that creates an anonymous function by compiling a string parameter, and it seems to work pretty well: def fn( text): exec 'def foo' + text.strip() return foo This can be used like: def foo( x): print x( 2, 5) foo( fn( ''' ( x, y): print 'x^2 + y^2 = ', x*x + y*y return y ''')) - which outputs: x^2 + y^2 = 29 5 You can also mimic conventional function definitions: f = fn( ''' ( x, y): print 'x, y=', x, y print 1.0*x/y return y ''') print 'calling f' f( 5, 6) This outputs: calling f x, y= 5 6 0.8333 You do things like allow/require an initial `def' for clarity, check that all the lines of text are indented so that nothing is executed when the anonymous function is created, etc etc. Obvious disadvantages are that the function text may have to escape quotes, and will not be showed with syntax colouring in editors. Apart from that, it seems quite a useful way of overcoming the limitations of python's lambda. But... I haven't seen this technique mentioned anywhere, so does anyone know of any problems that I should be wary of? - Julian -- http://www.op59.net/ -- http://mail.python.org/mailman/listinfo/python-list
Inconsistency in hex()
hex() of an int appears to return lowercase hex digits, and hex() of a long uppercase. hex(75) '0x4b' hex(75*256**4) '0x4BL' By accident or design? Apart from the aesthetic value that lowercase hex digits are ugly, should we care? It would also be nice if that trailing L would disappear. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Web App like Google
godwin wrote: Hello there, I need some thoughts about a web application that i am dreaming and drooling about in python. I want a search page to look exactly like Google. But when i press the search button, it should search a database in an rdbms like Oracle and provide results. For example, if my keywords are all customers with names starting with 'God' it should somehow search table CUSTOMER , with following query : SELECT CUSTNAME FROM CUSTOMER WHERE CUSTNAME LIKE 'God%' This is a Natural Language Processing (NLP) task. In general, it's pretty hard. For Python, there is the Natural Language Toolkit (NLTK): http://nltk.sourceforge.net/ You could get pretty far, though, by accepting a specific subset, the so-called controlled natural language approach. For example: http://www.jfsowa.com/clce/specs.htm http://www.ics.mq.edu.au/~rolfs/controlled-natural-languages/ http://www.ifi.unizh.ch/attempto/ -- 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: What is Expresiveness in a Computer Language?
Most participants in the computering industry should benefit in reading this essay: George Orwell's “Politics and the English Language”, 1946. Annotated: http://xahlee.org/p/george_orwell_english.html Xah [EMAIL PROTECTED] ∑ http://xahlee.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: how to stop execution in interactive window?
Right-click on the Pythonwin icon in the tray and select Break into running code. [CUT] Thanks a lot! Oddly enough I'm looking into PythonWin manual to see why I did not find it before... and there is no mention of it! Now if only I could find out how to free pythonwin interactive window memory (I'm not talking about interactive window output - cleanable with ctrl-a + delete, but about variable valorization, function definition etc )... IIRC there was already a post in this newsgroup that explained how to do this... but yesterday google searches return me that the only way was to force this by closing and re-opening pythonwin... Maybe I was wrong and there's no other way... Again: thanks a lot for your help! bye, PiErre -- http://mail.python.org/mailman/listinfo/python-list
Re: automatically assigning names to indexes
[EMAIL PROTECTED] wrote: I know its been done before, but I'm hacking away on a simple Vector class. class Vector(tuple): def __add__(self, b): return Vector([x+y for x,y in zip(self, b)]) def __sub__(self, b): return Vector([x-y for x,y in zip(self, b)]) def __div__(self, b): return Vector([x/b for x in self]) def __mul__(self, b): return Vector([x*b for x in self]) I like it, because it is simple, and can work with vectors of any size... However, I'd like to add attribute access (magically), so I can do this: v = Vector((1,2,3)) print v.x print v.y print v.z as well as: print v[0] print v[1] print v[2] Has anyone got any ideas on how this might be done? And what should happen for vectors of size != 3 ? I don't think that a general purpose vector class should allow it; a Vector3D subclass would be more natural for this. George -- http://mail.python.org/mailman/listinfo/python-list
Re: a new Python Podcast series (and the use of Python in creating podcasting tools)
I'd love to get some guest lectures from advanced folks, and interviews with prominent Pythonista people etc. Ron -- http://mail.python.org/mailman/listinfo/python-list
Re: Managment of Python Libraries
Joseph Chase wrote: In the past, I have noticed that I have spent a lot of time managing my C++ libraries. The main thing you need are good tests. -- Benji York -- http://mail.python.org/mailman/listinfo/python-list
Software needed
Hi Can anyone direct me to where I can find free software to do the following: Document Management Software --- 1. Written in PHP or Python 2. scanning feature - where I can scan a document I'm basically trying to setup a paperless office..lol If you could help that would be great. Thanx -- http://mail.python.org/mailman/listinfo/python-list
Re: cursor positioning
Danny Milosavljevic wrote: Hi, Examples ESC[2JESC[H same as clear, clear screen, go home \rESC[Kprogress %dprobably what you want :) Well, like the good old Commodore times :) Thank you. Mage -- http://mail.python.org/mailman/listinfo/python-list
Re: Should I use if or try (as a matter of speed)?
Edvard Majakari wrote: first make it work, then make it right, then make it fast Shouldn't one avoid doing it the wrong way from the very beginning? If you make it just work the first time, you'll probably use the old code later on because functionality is already there and temptatation to build on probably relatively bad architecture can be too strong. The expression describes (most recently, if not originally) the practice in Test-Driven Development (TDD) of making your code pass the test as quickly as possible, without worrying about how nice it is. The right part doesn't refer to correctness, but to structure, style, readability, and all those other nice things that an automated test can't check. You aren't doing it wrong at first, just expediently. And it really does make sense, because at that early stage, you aren't even absolutely certain that your test is entirely correct, so making your code a paragon of elegance is a potential waste of time, and distracting. Once you've been able to pass that test (and all the others, since you have to make sure all previous tests still pass as well), then and only then is it sensible -- and required! -- to refactor the code to make it elegant, concise, clean, etc. Of course, your point about temptation is sound. Extreme Programming tries to avoid that problem partly by pairing programmers together, and it is the responsibility of both partners to encourage^H^H^H^H^H insist that the refactor make it right stage must occur _now_, before we check the code in. If you skip this step, you're failing to be an agile programmer, and your code base will become a tar pit even more quickly than it would in a traditional (non-agile) project... -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: math.nroot [was Re: A brief question.]
I doubt anyone else is reading this by now, so I've trimmed quotes fairly ruthlessly :) Tim Peters [EMAIL PROTECTED] writes: Actually, I think I'm confused about when Underflow is signalled -- is it when a denormalized result is about to be returned or when a genuine zero is about to be returned? Underflow in 754 is involved -- indeed, the definition is different depending on whether the underflow trap is or is not enabled(!). ! Sure, but we already have a conforming implementation of 854 with settable traps and flags and rounding modes and all that jazz. No, we don't, but I assume you're talking about the decimal module. Uh, yes. Apologies for the lack of precision. If so, the decimal module enables traps on overflow, invalid operation, and divide-by-0 by default. A conforming implementation would have to disable them by default. Apart from that difference in defaults, the decimal module does intend to conform fully to the proposed decimal FP standard. Right, that's what I meant. Maybe we should just implement floats in Python. Certainly the easiest way to get 754 semantics across boxes! Been there, done that, BTW -- it's mondo slow. No doubt. (In the mean time can we just kill fpectl, please?) Has it been marked as deprecated yet (entered into the PEP for deprecated modules, raises deprecation warnings, etc)? I don't know. IMO it should become deprecated, but I don't have time to push that. A bit of googling suggests that more people pass --with-fpectl to configure than I expected, but I doubt more than 1% of those actually use the features thus provided (of course, this is a guess). I expect 1% is way high. Before we stopped building fpectl by default, Guido asked and heard back that there were no known users even at LLNL anymore (the organization that contributed the code). Interesting. You're seeing native HW fp behavior then. But anyway, shouldn't we try to raise exceptions in these cases? Note that the only cases you could have been talking about here were the plain * and / examples above. Ah, OK, this distinction passed me by. Why doesn't Python already supply a fully 754-conforming arithmetic on 754 boxes? It's got almost everything to do with implementation headaches, and very little to do with what users care about. Because all the C facilities are a x-platform mess, the difference between calling and not calling libm can be the difference between using the platform libm or Python needing to write its own libm. For example, there's no guarantee that math.sqrt(-1) will raise ValueError in Python, because Python currently relies on the platform libm sqrt to detect _and report_ errors. The C standards don't require much of anything there. Can't we use the stuff defined in Appendix F and header fenv.h of C99 to help here? I know this stuff is somewhat optional, but it's available AFAICT on the platforms I actually use (doesn't mean it works, of course). It's entirely optional part of C99. Hmm, is fenv.h optional? I'm not finding those words. I know Appendix F is. Python doesn't require C99. Sure. But it would be possible to, say, detect C99 floating point facilities at ./configure time and use them if available. The most important example of a compiler that doesn't support any of that stuff is Microsoft's, although they have their own MS-specific ways to spell most of it. OK, *that's* a serious issue. If you had to guess, do you think it likely that MS would ship fenv.h in the next interation of VC++? I'm thinking something like this: fexcept_t flags; feclearexcept(FE_ALL_EXCEPT); /* stuff, e.g. r = exp(PyFloat_AS_DOUBLE(x)) */ fegetexceptflag(flags, FE_ALL_EXCEPT) /* inspect flags to see if any of the flags we're currently trapping are set */ Assuming the platform libm sets 754 flags appropriately, that's a fine way to proceed on platforms that also support that specific spelling. It even seems to work, on darwin/ppc (so, with GCC) at least. ... Well, you can at least be pretty sure that an infinite result is the result of an overflow condition, I guess. There are at least two other causes: some cases of divide-by-0 (like 1/0 returns +Inf), and non-exceptional production of an infinite result from infinite operands (like sqrt(+Inf) should return +Inf, and there's nothing exceptional about that). Yeah, but I think those can be dealt with (if we really wanted to). They certainly could be. The more I think about it, the less wise I think detecting stuff this was is sane. BTW, since there's so little the HW can help us with here in reality (since there's no portable way to get at it), In what way does C99's fenv.h fail? Is it just insufficiently available, or is there some conceptual lack? Just that it's not universally supported. Look at fpectlmodule.c for a sample of the wildly different
Re: relative import packages/modules workaround
hmm, it seems to be less trivial than you mentioned... hopefully this will be introduced fast in python -- http://mail.python.org/mailman/listinfo/python-list
Re: Search Replace with RegEx
[EMAIL PROTECTED] wrote:
[snipped]
For example, after installing a new extension, I change in compreg.dat
lines such as:
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{0538E3E3-7E9B-4d49-8831-A227C80A7AD3}\components\nsForecastfox.js,18590
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{c4dc572a-3295-40eb-b30f-b54aa4cdc4b7}\components\wml-service.js,111470502
to:
rel:nsForecastfox.js,18590
rel:wml-service.js,111470502
Try this:
import re
from fileinput import FileInput
regex = re.compile(r'^abs:.*\\(.+)$')
input = FileInput(filename)
unparsed = []
for line in input:
try:
print regex.match(line).group(1)
except:
unparsed.append(input.filelineno())
print line
print Unparsed lines:, ','.join(map(str,unparsed))
George
--
http://mail.python.org/mailman/listinfo/python-list
Re: Tricky Dictionary Question from newbie
Notice the dictionary is only changed if the key was missing.
a = {}
a.setdefault(a, 1)
'1'
a.setdefault(a, 2)
'1'
a.setdefault(b, 3)
'3'
a
{'a': '1', 'b': '3'}
a.setdefault(a, 5)
'1'
a
{'a': '1', 'b': '3'}
-Jim
On 7/11/05, Peter Hansen [EMAIL PROTECTED] wrote:
Ric Da Force wrote:
How does setdefault work exactly? I am looking in the docs and can't figure
it out...
If the key (the first argument) already exists in the dictionary, the
corresponding value is returned. If the key does not exist in the
dictionary, it is stored in the dictionary and bound to the second
argument, and then that second argument is returned as the value.
(I always have to ignore the name to think about how it works, or it
gets in the way of my understanding it. The name makes fairly little
sense to me.)
-Peter
--
http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
Re: Parsing Data, Storing into an array, Infinite Backslashes
Thanks for all the help, I'm not sure what approach I'm going to try but I think I'll try all of your suggestions and see which one fits best. The variable i held the following array: [['Memory', '0', 'Summary', '0'], ['Memory', '0', 'Speed', 'PC3200U-30330'], ['Memory', '0', 'Type', 'DDR SDRAM'], ['Memory', '0', 'Size', '512'], ['Memory', '0', 'Slot', 'DIMM0/J11'], ['Memory', '0', 'ConfigurationType', '2'], ['Memory', '1', 'Summary', '0'], ['Memory', '1', 'Speed', 'PC3200U-30330'], ['Memory', '1', 'Type', 'DDR SDRAM'], ['Memory', '1', 'Size', '512'], ['Memory', '1', 'Slot', 'DIMM1/J12'], ['Memory', '1', 'ConfigurationType', '2'], ['Memory', '2', 'Summary', '0'], ['Memory', '2', 'Speed', 'PC3200U-30330'], ['Memory', '2', 'Type', 'DDR SDRAM'], ['Memory', '2', 'Size', '512'], ['Memory', '2', 'Slot', 'DIMM2/J13'], Where is the fetch object defined? And what is it supposed to be returning? Fetch is declared a few lines up in the program with this fetch=iter(ed) it just goes through the array and returns the next part of it. query[count]=qval+i[2]+=+i[3]+, Impossible to know what this does since we don't know what i is. Hint: it is easier to read and parse expressions by adding a small amount of whitespace: I am trying to assign each new memory slot to a new part in the array. So when memory is either 0,1,2,3 it will assign it to query[0], query[1], query[2], query[3] -- http://mail.python.org/mailman/listinfo/python-list
Re: Tricky Dictionary Question from newbie
(Fixed top-posting) James Carroll wrote: On 7/11/05, Peter Hansen [EMAIL PROTECTED] wrote: (I always have to ignore the name to think about how it works, or it gets in the way of my understanding it. The name makes fairly little sense to me.) Notice the dictionary is only changed if the key was missing. James, I'll assume your reply was intended to address my comment above. It's not so much that the concept of set the default value for this key is poorly captured by the name setdefault, but that the function is used almost exclusively in the idiom below, where it is critical that it also _returns_ the value, which is usually then operated on immediately, usually in the same line of code. dict.setdefault(key, defaultValue).someMethodOnKey() or dict.setdefault(key, defaultValue) #= value, where # is some operator. I suppose I shouldn't blame setdefault() itself for being poorly named, but it's confusing to me each time I see it in the above, because the name doesn't emphasize that the value is being returned, and yet that fact is arguably more important than the fact that a default is set! I can't think of a better name, though, although I might find foo less confusing in the above context. :-) -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: automatically assigning names to indexes
[EMAIL PROTECTED] I know its been done before, but I'm hacking away on a simple Vector class. [...] However, I'd like to add attribute access (magically), so I can do this: [...] Has anyone got any ideas on how this might be done? I needed something this last week, while toying with rotations. Allow me to humbly offer my solution, meant for more than one class. Yet for brievety, I'm limiting my example to a single class. A few constructors are used in the example, but the corresponding classes are missing. I hesitated a bit between having my rotation objects be modifiable or not, and finally opted for the later (consequently, the constructor is neatly called for a resulting object). If you really want a modifiable object, derive from `list' instead of deriving from `tuple', rename `NamedTuple' into `NamedList', and wihin sub-classes, initialise your object with `__init__(self, ...)' rather than with `__new__(cls, ...)'. __metaclass__ = type import math # Almost zero, but not yet. epsilon = 1e-9 from math import pi half_pi = .5*pi class NamedTuple(tuple): class __metaclass__(type): def __new__(cls, name, bases, definitions): self = type.__new__(cls, name, bases, definitions) if hasattr(self, '__names__'): def make_property(index): def getter(self): return self[index] return property(getter) for index, name in enumerate(self.__names__): setattr(self, name, make_property(index)) return self class Quaternion(NamedTuple): __names__ = 'w', 'x', 'y', 'z' def __new__(cls, w, x, y, z): l = 1./math.sqrt(w*w + x*x + y*y + z*z) return cls.new(w*l, x*l, y*l, z*l) def new(cls, w, x, y, z): if w 0.: self = tuple.__new__(cls, (-w, -x, -y, -z)) else: self = tuple.__new__(cls, (w, x, y, z)) assert self.is_normal(), self return self new = classmethod(new) def is_normal(self): # For debugging only. w, x, y, z = self return abs(w*w + x*x + y*y + z*z - 1.) epsilon and w = 0. def __eq__(self, other): w1, x1, y1, z1 = self w2, x2, y2, z2 = other return abs(w1-w2) + abs(x1-x2) + abs(y1-y2) + abs(z1-z2) epsilon def __ne__(self, other): return not self == other def __mul__(self, other): w1, x1, y1, z1 = self w2, x2, y2, z2 = other return Quaternion.new(w1*w2 - x1*x2 - y1*y2 - z1*z2, w1*x2 + x1*w2 + y1*z2 - z1*y2, w1*y2 + y1*w2 - x1*z2 + z1*x2, w1*z2 + z1*w2 + x1*y2 - y1*x2) def __div__(self, other): w1, x1, y1, z1 = self w2, x2, y2, z2 = other return Quaternion.new( w1*w2 + x1*x2 + y1*y2 + z1*z2, -w1*x2 + x1*w2 - y1*z2 + z1*y2, -w1*y2 + y1*w2 + x1*z2 - z1*x2, -w1*z2 + z1*w2 - x1*y2 + y1*x2) def __rdiv__(self, other): if not isinstance(other, (int, long, float)): raise TypeError(unsupported operand type(s) for /) w, x, y, z = self return Quaternion.new(w, -x, -y, -z) __truediv__ = __div__ __rtruediv__ = __rdiv__ def euler(self): w, x, y, z = self x2 = x + x y2 = y + y z2 = z + z xx2 = x2*x yy2 = y2*y zz2 = z2*z wx2 = x2*w wy2 = y2*w wz2 = z2*w xy2 = x2*y yz2 = y2*z zx2 = z2*x siny = wy2 - zx2 if abs(abs(siny) - 1) epsilon: return Euler.new(math.asin(siny), math.atan2(yz2 + wx2, 1. - xx2 - yy2), math.atan2(xy2 + wz2, 1. - yy2 - zz2)) if siny 0.: y = half_pi else: y = -half_pi return Euler.new(math.atan2(-(yz2 - wx2), 1. - xx2 - zz2), y, 0.) def matrix(self): w, x, y, z = self x2 = x + x y2 = y + y z2 = z + z xx2 = x2*x yy2 = y2*y zz2 = z2*z wx2 = x2*w wy2 = y2*w wz2 = z2*w xy2 = x2*y yz2 = y2*z zx2 = z2*x return Matrix(1. - yy2 - zz2, xy2 + wz2, zx2 - wy2, xy2 - wz2, 1. - xx2 - zz2, yz2 + wx2, zx2 + wy2, yz2 - wx2, 1. - xx2 - yy2) -- François Pinard http://pinard.progiciels-bpi.ca -- http://mail.python.org/mailman/listinfo/python-list
Re: Puzzled
Bengt Richter wrote:
On Mon, 11 Jul 2005 22:10:33 -0400, Colin J. Williams [EMAIL PROTECTED]
wrote:
The snippet of code below gives the result which follows
for k in ut.keys():
name= k.split('_')
print '\n1', name
if len(name) 1:
name[0]= name[0] + name[1].capitalize()
print '2', name
name[0]= name[0].capitalize()
print '3', name
1 ['logical', 'or']
2 ['logicalOr', 'or']
3 ['Logicalor', 'or']
I was expecting that 3 would read ['LogicalOr', 'or']
If I replace the above code with:
for k in ut.keys():
name= k.split('_')
print '\n1', name
if len(name) 1:
name[0]= name[0].capitalize() + name[1].capitalize()
print '2', name
else:
name[0]= name[0].capitalize()
print '3', name
I get the desired result.
If you walk through the results, you can see what happens to name[2] on
output line 2:
'logicalOr'.capitalize()
'Logicalor'
I.e.,
help(str.capitalize)
Help on method_descriptor:
capitalize(...)
S.capitalize() - string
Return a copy of the string S with only its first character
capitalized. -- meaning all the rest
lowercased,
which changed your trailing
'Or'
So, doing .capitalize on all the pieces from split('_') and then joining them:
def doit(w): return ''.join([s.capitalize() for s in w.split('_')])
...
doit('logical_or')
'LogicalOr'
doit('logical')
'Logical'
doit('logical_or_something')
'LogicalOrSomething'
doit('UP_aNd_down')
'UpAndDown'
Regards,
Bengt Richter
Many thanks. I missed the implication that any upper case characters
after the first are changed to lower case.
Colin W.
--
http://mail.python.org/mailman/listinfo/python-list
Missing Something Simple
Hi, I have a list of variables, which I am iterating over. I need to set the value of each variable. My code looks like: varList = [ varOne, varTwo, varThree, varFour ] for indivVar in varList: indivVar = returnVarFromFunction() However, none of the variables in the list are being set. I thought of using setattr, but this code sits in a function, and not class, so I'm unsure what the object would be. I'm hoping someone can point me in the right direction. John -- http://mail.python.org/mailman/listinfo/python-list
append one file to another
Hi, I want to append one (huge) file to another (huge) file. The current way I'm doing it is to do something like: infile = open (infilename, 'r') filestr = infile.read() outfile = open(outfilename, 'a') outfile.write(filestr) I wonder if there is a more efficient way doing this? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
CONNCET TO SOAP SERVICE
Can you help me plz? I want to wonnect to SOAP webservices but before I must be authentificated on a apache server, I used SOAPpy module but I dont know how I can be authentified on the apache server thx Slaheddine Haouel Unilog NORD tél : 03 59 56 60 25 tél support : 03 59 56 60 68 Email : [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
RE: Yet Another Python Web Programming Question
FWIW there's dos2unix program that fixes this on most systems. -Original Message- From: Bill Mill [mailto:[EMAIL PROTECTED] Sent: Monday, July 11, 2005 11:55 AM To: Daniel Bickett Cc: python-list@python.org Subject: Re: Yet Another Python Web Programming Question Python using CGI, for example, was enough for him until he started getting 500 errors that he wasn't sure how to fix. A common error is that python cgi files need line endings to be in unix text file format, not windows text file format (\n instead of \r\n) [1]. Why this is, I don't know, but it causes a lot of errors for windows folks. I'm a frequent linux/windows switcher, and it's caused me no end of troubles - if you're getting premature end of script headers in your apache error logs, this may be your problem. Peace Bill Mill bill.mill at gmail.com -- http://mail.python.org/mailman/listinfo/python-list --- The information contained in this message may be privileged and / or confidential and protected from disclosure. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by replying to this message and deleting the material from any computer. --- -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
Am Tue, 12 Jul 2005 06:47:50 -0700 schrieb [EMAIL PROTECTED]: Hi, I want to append one (huge) file to another (huge) file. The current way I'm doing it is to do something like: infile = open (infilename, 'r') filestr = infile.read() outfile = open(outfilename, 'a') outfile.write(filestr) I wonder if there is a more efficient way doing this? Thanks. I guess (don't know), that this is faster: for line in infile: outfile.write(line) At least if this a file with lines. If it is a binary file, you could read N bytes at once: infile.read(N) Thomas -- Thomas Güttler, http://www.thomas-guettler.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Search Replace with RegEx
Am Tue, 12 Jul 2005 01:11:44 -0700 schrieb [EMAIL PROTECTED]:
Hi Pythonistas,
Here's my problem: I'm using a version of MOOX Firefox
(http://moox.ws/tech/mozilla/) that's been modified to run completely
from a USB Stick. It works fine, except when I install or uninstall an
extension, in which case I then have to physically edit the compreg.dat
file in my profile directory, replacing all instances of Absolute Path
links to relative ones. (And, yes, I have filed a Bugzilla report.)
For example, after installing a new extension, I change in compreg.dat
lines such as:
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{0538E3E3-7E9B-4d49-8831-A227C80A7AD3}\components\nsForecastfox.js,18590
abs:J:\Firefox\Firefox_Data\Profiles\default.uyw\extensions\{c4dc572a-3295-40eb-b30f-b54aa4cdc4b7}\components\wml-service.js,111470502
to:
rel:nsForecastfox.js,18590
rel:wml-service.js,111470502
Hi,
some time ago I wrote replace-recursive.py:
http://www.thomas-guettler.de/scripts/replace_recursive.py.txt
Maybe this helps you,
Thomas
--
Thomas Güttler, http://www.thomas-guettler.de/
--
http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
Hi, I have a list of variables, which I am iterating over. I need to set the value of each variable. My code looks like: varList = [ varOne, varTwo, varThree, varFour ] for indivVar in varList: indivVar = returnVarFromFunction() However, none of the variables in the list are being set. You only change the value of the local variable in the body of the for loop. it has no effect on the list. you could do e.g. varList = [vorOne,varTwo,varThree,varFour] for i in len(varList) : varList[i] = returnVarFromFunction() However, as in this example the former list values are not used anyway, you could just write: varList = [ returnVarFromFunction for i varList ] cheers, - harold - -- Tages Arbeit, abends Gäste, saure Wochen, frohe Feste! -- Johann Wolfgang v. Goethe -- http://mail.python.org/mailman/listinfo/python-list
CAD in wxPython
Hi all, I am trying to write a small program to view VLSI mask layouts. I am trying to display polygons with different *transparent* patterns. How can I do this in wxPython. Can you please give me some pointers if some application has already done this. Look at the images in these web pages. I am trying to create something like this. http://vsp2.ecs.umass.edu/vspg/658/TA_Tools/cadence/Vertuoso.html http://www.cisl.columbia.edu/grads/sumit/layout.html My dream is to develop a full fledged eda environment on top of python. If you are also interested contact me. Thanks. regards, Suresh -- http://mail.python.org/mailman/listinfo/python-list
Re: automatically assigning names to indexes
And what should happen for vectors of size != 3 ? I don't think that a general purpose vector class should allow it; a Vector3D subclass would be more natural for this. That's the 'magic' good idea I'm looking for. I think a unified Vector class for all size vectors is a worthy goal! -- http://mail.python.org/mailman/listinfo/python-list
Re: Tricky Dictionary Question from newbie
Oops.. Gmail just normally puts the reply to at the bottom of the discussion... so by default I reply to the list, and the last person to post. My comment was not directed at you. I just posted the contents of an interactive session that I did to better understand setdefault myself. I've got to remind myself to change the reply-to address to the list. (other lists do this by default, why not this one?) I agree that the name doesn't ring quite right to me either. I kind of understand what the creator of the function was getting at... it's kind of like when you want to retrieve a configuration variable from a container, but if it's not there, then you want to use a default: storedWidth = container.GetConfigurationValue(name = width, default=500) If there is a width stored, it will retrieve that, otherwise it will give you the default that you specified in the second parameter. It makes it easier than checking for existance, then retrieving or assigning a default. Setdefault, in my mind is really a _get_ kind of operation. It retrieves from the dictionary most of the time, and only does anything different when the key doesn't exist, and then does an assignment... so my next guess at a better name for setdefault would be: value = container.GetOrAddDefault(key=a, default=[]) value.append(listvalue) but that's kind of confusing too, but it better describes what is happening. -Jim On 7/12/05, Peter Hansen [EMAIL PROTECTED] wrote: (Fixed top-posting) James Carroll wrote: On 7/11/05, Peter Hansen [EMAIL PROTECTED] wrote: (I always have to ignore the name to think about how it works, or it gets in the way of my understanding it. The name makes fairly little sense to me.) Notice the dictionary is only changed if the key was missing. James, I'll assume your reply was intended to address my comment above. -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
harold fellermann wrote: Hi, I have a list of variables, which I am iterating over. I need to set the value of each variable. My code looks like: varList = [ varOne, varTwo, varThree, varFour ] for indivVar in varList: indivVar = returnVarFromFunction() However, none of the variables in the list are being set. You only change the value of the local variable in the body of the for loop. it has no effect on the list. you could do e.g. varList = [vorOne,varTwo,varThree,varFour] for i in len(varList) : varList[i] = returnVarFromFunction() However, as in this example the former list values are not used anyway, you could just write: varList = [ returnVarFromFunction for i varList ] cheers, - harold - -- Tages Arbeit, abends Gäste, saure Wochen, frohe Feste! -- Johann Wolfgang v. Goethe The problem I have, is the variables are referenced elsewhere. They have been declared before being used in the list. Basically, I'm after the Python way of using deferencing. J -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
have been declared before being used in the list. Basically, I'm after the Python way of using deferencing. OK, that should say dereferencing. J -- http://mail.python.org/mailman/listinfo/python-list
breaking out of nested loop
What is the appropriate way to break out of this while loop if the for loop finds a match? while 1: for x in xrange(len(group)): try: mix = random.sample(group, x) make_string = ''.join(mix) n = md5.new(make_string) match = n.hexdigest() if match == target: print Collision!!! print make_string Stop = time.strftime(%H:%M:%S-%m-%d-%y, time.localtime()) print Stop, Stop break else: continue except Exception, e: print e -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
Am Tue, 12 Jul 2005 14:44:00 +0100 schrieb John Abel: Hi, I have a list of variables, which I am iterating over. I need to set the value of each variable. My code looks like: varList = [ varOne, varTwo, varThree, varFour ] for indivVar in varList: indivVar = returnVarFromFunction() However, none of the variables in the list are being set. I thought of using setattr, but this code sits in a function, and not class, so I'm unsure what the object would be. Hi, indivVar is a *reference* to a value. You only change the reference, not the value. Maybe this code helps you: a=a b=b c=c varList = [a, b, c] for x in varList: x = foo # nothing changed print varList # -- [a, b, c] for i in range(len(varList)): varList[i]=foo # List was changed print varList # -- [foo, foo, foo] HTH, Thomas -- Thomas Güttler, http://www.thomas-guettler.de/ -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
On Tue, 12 Jul 2005 06:47:50 -0700, [EMAIL PROTECTED] wrote: Hi, I want to append one (huge) file to another (huge) file. What do you call huge? What you or I think of as huge is not necessarily huge to your computer. The current way I'm doing it is to do something like: infile = open (infilename, 'r') filestr = infile.read() outfile = open(outfilename, 'a') outfile.write(filestr) I wonder if there is a more efficient way doing this? Why? Is it not working? Is it too slow? Does it crash your computer? If you have any expectation that you code needs to run under Windows, or cross-platform, or contains binary data, you should open your files in binary mode: infile = open(infilename, 'rb') outfile = open(outfilename, 'ab') For raw copying, you should probably use binary mode even if they just contain text. Better safe than sorry... Then, if you are concerned that the files really are huge, that is, as big or bigger than the free memory your computer has, read and write them in chunks: data = infile.read(64) # 64 bytes at a time is a bit small... outfile.write(data) Instead of 64 bytes, you should pick a more realistic figure, which will depend on how much free memory your computer has. I suppose a megabyte is probably reasonable, but you will need to experiment to find out. Then when you are done, close the files: infile.close() outfile.close() This is not strictly necessary, but it is good practice. If your program dies, the files may not be closed properly and you could end up losing data. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Yet Another Python Web Programming Question
Daniel Bickett [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] snip It was his opinion that web programming should feel no different from desktop programming. snip Should that ever become even remotely possible - I'll be interested in web programming myself. Thomas Bartkus -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
Hello John,
John Abel wrote:
harold fellermann wrote:
Hi,
I have a list of variables, which I am iterating over. I need to set
the value of each variable. My code looks like:
varList = [ varOne, varTwo, varThree, varFour ]
for indivVar in varList:
indivVar = returnVarFromFunction()
However, none of the variables in the list are being set.
You only change the value of the local variable in the body
of the for loop. it has no effect on the list. you could do e.g.
varList = [vorOne,varTwo,varThree,varFour]
for i in len(varList) :
varList[i] = returnVarFromFunction()
However, as in this example the former list values are not used anyway,
you could just write:
varList = [ returnVarFromFunction for i varList ]
cheers,
- harold -
--
Tages Arbeit, abends Gäste,
saure Wochen, frohe Feste!
-- Johann Wolfgang v. Goethe
The problem I have, is the variables are referenced elsewhere. They
have been declared before being used in the list. Basically, I'm after
the Python way of using deferencing.
The problem you have is that you don't understand the way that Python
references objects.
All Python names (aka variables) are references. You can rebind a name
to *any* object, but you can only change *some* objects. These are
called the mutable datatypes. The ones you can't changed are called
immutable types.
This is a common Python gotcha - but it's an integral part of the way
Python works - not a wart.
Your problem (I think) is that you have something like :
myVar = 'hello'
another_name = myVar
another_name = 'goodbye'
print myVar
'hello'
but you expected 'goodbye'.
What you have done in the first line is created a new - a string with
the contents 'hello' - and bound the name
In the second line you bind another name to the *same* object. (You
*don't* bind the second name to the first name, but to the object it
references).
In the third line you create a new object and *rebind* the second name.
You haven't chanegd the underlying object. In Python the string is
immutable. This means it's hashable and can be used as a dictionary
key.
If you want to maintain a reference to a *location* then use a mutable
datatype. Instead of a list use a dictionary, keyed by name (as one
example).
e.g. a_dict = {'name1': object1, 'name2': object2}
Even if you change the contents of the dictionaries, the names will
still point to what you expect. (And you can still iterate over a
dictionary).
Before you get much further in Python you'll need a clearer
understanding of the difference between it's objects and names.
Best Regards,
Fuzzy
http://www.voidspace.org.uk/python
J
--
http://mail.python.org/mailman/listinfo/python-list
question on input
Hi,
I want to accept the user's answer yes or no.
If I do this:
answer = input('y or n?')
and type y on the keyboard, python complains
Traceback (most recent call last):
File stdin, line 1, in ?
File string, line 0, in ?
NameError: name 'y' is not defined
It seems like input only accepts numerals, or strings with quotes.
Need solutions, thanks.
--
http://mail.python.org/mailman/listinfo/python-list
Re: question on input
On 12 Jul 2005 07:31:47 -0700, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
Hi,
I want to accept the user's answer yes or no.
If I do this:
answer = input('y or n?')
Use raw_input instead:
answer = raw_input(y or n?)
y or n?y
answer
'y'
Check out the documentation of both functions at
http://docs.python.org/lib/built-in-funcs.html for more details.
snip
Peace
Bill Mill
--
http://mail.python.org/mailman/listinfo/python-list
Re: Software needed
Sounds like the sort of project that could work as a plugin to chandler. There's a Python interface to TWAIN (the scanner protocol) - but I'm not *aware* of anything built on top of it. google may have a better idea though. Regards, Fuzzy http://www.voidspace.org.uk/python -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
Thanks for the nice suggestions! As a side question, you mentioned opening files in binary mode, in case the code needs to run under Windows or cross-platform. What would happen otherwise? Is it an issue of big little endian or some other issue? -- http://mail.python.org/mailman/listinfo/python-list
Re: question on input
Use raw_input instead. It returns a string of whatever was typed. Input expects a valid python expression. -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
Dear me, replying to myself twice in one day... On Wed, 13 Jul 2005 00:39:14 +1000, Steven D'Aprano wrote: Then, if you are concerned that the files really are huge, that is, as big or bigger than the free memory your computer has, read and write them in chunks: data = infile.read(64) # 64 bytes at a time is a bit small... outfile.write(data) Sorry, that should be in a loop: data = anything while data: data = infile.read(64) # data will be empty when the file is read outfile.write(data) -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
You either need to set a marker flag with multiple breaks - *or* (probably more pythonic) wrap it in a try..except and raise an exception. Define your own exception class and just trap for that if you want to avoid catching other exceptions. There is no single command to break out of multiple loops. Regards, Fuzzy http://www.voidspace.org.uk/python -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
I have a list of variables, which I am iterating over. I need to set the value of each variable. My code looks like: varList = [ varOne, varTwo, varThree, varFour ] for indivVar in varList: indivVar = returnVarFromFunction() However, none of the variables in the list are being set. You only change the value of the local variable in the body of the for loop. it has no effect on the list. you could do e.g. varList = [vorOne,varTwo,varThree,varFour] for i in len(varList) : varList[i] = returnVarFromFunction() However, as in this example the former list values are not used anyway, you could just write: varList = [ returnVarFromFunction for i varList ] The problem I have, is the variables are referenced elsewhere. They have been declared before being used in the list. Basically, I'm after the Python way of using deferencing. so, if I understand you right, what you want to have is a list of mutable objects, whose value you can change without changing the objects' references. class Proxy : def __init__(self,val) : self.set(val) def set(self,val) : self.val = val def get(self) : return self.val a = Proxy(1) b = Proxy(2) c = Proxy(3) varList = [a,b,c] for i in varList : i.set(returnVarFromFunction()) print a,b,c prints whatever returnVarFromFunction has returned. n.b.: instead of the Proxy class, you can use any other mutable objects, e.g. lists. - harold - -- All unsere Erfindungen sind nichts als verbesserte Mittel zu einem nicht verbesserten Zweck. -- H.D. Thoreau -- http://mail.python.org/mailman/listinfo/python-list
Help with inverted dictionary
I'm new to Python and I'm struggling. I have a text file (*.txt) with a couple thousand entries, each on their own line (similar to a phone book). How do I make a script to create something like an inverted dictionary that will allow me to call robert and create a new text file of all of the lines that contain robert? Thanks so much. -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
rbt wrote: What is the appropriate way to break out of this while loop if the for loop finds a match? Define a flag first: keepGoing = True while 1: while keepGoing: for x in xrange(len(group)): try: ... if match == target: print Collision!!! print make_string Set the flag here, then do the break: keepGoing = False break Tada... -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
Its been a while since I last coded in Python, so please make sure you test it before trying it so you don't clobber your existing file. Although it may not be more effecient than what you are doing now or has been suggested already, it sure cuts down on the typing. open(outfilename,'a').write(open(infilename).read()) Regards. [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Hi, I want to append one (huge) file to another (huge) file. The current way I'm doing it is to do something like: infile = open (infilename, 'r') filestr = infile.read() outfile = open(outfilename, 'a') outfile.write(filestr) I wonder if there is a more efficient way doing this? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
Thanks guys... that works great. Now I understand why sometimes logic such as 'while not true' is used ;) On Tue, 2005-07-12 at 10:51 -0400, Peter Hansen wrote: rbt wrote: What is the appropriate way to break out of this while loop if the for loop finds a match? Define a flag first: keepGoing = True while 1: while keepGoing: for x in xrange(len(group)): try: ... if match == target: print Collision!!! print make_string Set the flag here, then do the break: keepGoing = False break Tada... -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
rbt wrote: What is the appropriate way to break out of this while loop if the for loop finds a match? while 1: for x in xrange(len(group)): another option not yet suggested is simply to collapse the two loops into a single loop: import itertools for x in itertools.cycle(range(len(group)): ... as before ... -- http://mail.python.org/mailman/listinfo/python-list
Re: Missing Something Simple
harold fellermann wrote: so, if I understand you right, what you want to have is a list of mutable objects, whose value you can change without changing the objects' references. Yes! class Proxy : def __init__(self,val) : self.set(val) def set(self,val) : self.val = val def get(self) : return self.val a = Proxy(1) b = Proxy(2) c = Proxy(3) varList = [a,b,c] for i in varList : i.set(returnVarFromFunction()) print a,b,c prints whatever returnVarFromFunction has returned. n.b.: instead of the Proxy class, you can use any other mutable objects, e.g. lists. - harold - -- All unsere Erfindungen sind nichts als verbesserte Mittel zu einem nicht verbesserten Zweck. -- H.D. Thoreau That does it. Thank you! J -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
On Tue, 12 Jul 2005 10:19:04 -0400, rbt wrote: What is the appropriate way to break out of this while loop if the for loop finds a match? Refactor it into something easier to comprehend? And comments never go astray. (Untested. And my docstrings are obviously bogus.) def make_one_thing(group, x): Makes a thing by plonking the frobber. Expects group to be a list of foo and x to be an index. mix = random.sample(group, x) make_string = ''.join(mix) n = md5.new(make_string) match = n.hexdigest() return match def group_matches(group, target): Cycles over a group of foos, plonking the frobber of each item in turn, and stopping when one equals target. for x in xrange(len(group)): try: match = make_one_thing(group, x) if match == target: return True except Exception, e: # don't stop just because the program has a bug print e # if we get here, there was no successful match after the # entire for loop return False def test_until_success: Loop forever, or until success, whichever comes first. group = [1, 2, 3, 4] target = 5 flag = False while not flag: print No matches yet, starting to search... flag = group_matches(group, target) # if we ever get here, it means we found a collision, and # flag became True, so the while loop just dropped out print Collision!!! stop = time.strftime(%H:%M:%S-%m-%d-%y, time.localtime()) print Stopped at, stop -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
On 2005-07-12, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: As a side question, you mentioned opening files in binary mode, in case the code needs to run under Windows or cross-platform. What would happen otherwise? Is it an issue of big little endian or some other issue? The end-of-line characters might get converted -- even if they're not really end-of-line characters in the file in question. -- Grant Edwards grante Yow! My mind is a potato at field... visi.com -- http://mail.python.org/mailman/listinfo/python-list
Why does reply to messages on this list put the sender in the To
Most lists when i hit reply it puts the list address back in the To address and some lists allow you to configure this. But in this list reply sends the mail back as a private mail and there seems to be no option to configure this. Am I missing something DarkCowherd -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
Hello, First I'm not so clear about your problem, but you can do the following steps: 1. Transform your file into list (list1) 2. Use regex to capture 'robert' in every member of list1 and add to list2 3. Transform your list2 into a file pujo -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
import re
name = Robert
f = file('phonebook.txt','r')
lines = [line.rstrip(\n) for line in f.readlines()]
pat = re.compile(name, re.I)
related_lines = [line for line in lines if pat.search(line)]
And then you write the lines in related_lines to a file. I don't really
write text to files much so, um, yeah.
--
http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
rbt wrote: What is the appropriate way to break out of this while loop if the for loop finds a match? queue discussion why Python doesn't have a break N statement... -- Jeremy Sanders http://www.jeremysanders.net/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Thoughts on Guido's ITC audio interview
Tony Meyer wrote: Everyone complaining about Eclipse in this thread needs to go try 3.1. The interface is much much much more responsive. The problem with Eclipse, IMO, is Java. I've tried 3.1 on a WinXP machine and, like just about any Java program, it's incredibly slow and a real pain to use. On a (similarly spec'd) Mac OS X Tiger machine, it runs nice and smoothly and is reasonably nice to use. I'd happily recommend that Mac users try Eclipse, but never a Windows (Python) programmer. I've not tried Mac, but under both Windows and Linux on x86, I find Eclipse (3.0) is slow with less than 1.25 GB of RAM, reasonably fast with 1.5GB or more. Processor speed and disk speed don't seem to be anywhere near as important. -- http://mail.python.org/mailman/listinfo/python-list
RE: breaking out of nested loop
[Jeremy Sanders] | rbt wrote: | | What is the appropriate way to break out of this while loop | if the for | loop finds a match? | | queue discussion why Python doesn't have a break N statement... pedantry Presumably you meant cue discussion... /pedantry (Ducks runs) TJG This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
OK, so my problem is I have a text file with all of these instances, for example 5000 facts about animals. I need to go through the file and put all of the facts (lines) that contain the word lion into a file called lion.txt. If I come across an animal or other word for which a file does not yet exist I need to create a file for that word and put all instances of that word into that file. I realize that this should probably create 30,000 files or so. Any help would be REALLY appreciated. Thanks. Reece -- http://mail.python.org/mailman/listinfo/python-list
Re: breaking out of nested loop
rbt [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] What is the appropriate way to break out of this while loop if the for loop finds a match? Make it a function and use a return statement to break out. -- http://mail.python.org/mailman/listinfo/python-list
Web client, https and session management
Hello all, 2-3 years ago, I did a program in perl. Now I have to modify it and I want to rewrite it from scratch using Python. The program is doing this: 1- Load Yahoo login webpage (https) 2- Log into Yahoo website using my personal login and password. 3- Grasp and extract some information from my mailing lists messages (http, not https). My questions are: - Is it possible to do this using Python? - How? To acheive point #3, which is the goal, my web client has to manage session (because of the login aspect). This is the part I don't know how it's working. Any help would be appreciated. Thanks. Yannick -- http://mail.python.org/mailman/listinfo/python-list
Re: Creating anonymous functions using eval
How is this different from a nested function? -- http://mail.python.org/mailman/listinfo/python-list
Re: Why does reply to messages on this list put the sender in the To
On 7/12/05, Dark Cowherd [EMAIL PROTECTED] wrote: Most lists when i hit reply it puts the list address back in the To address and some lists allow you to configure this. But in this list reply sends the mail back as a private mail and there seems to be no option to configure this. Am I missing something Nope, it's a preference set by the list managers. There are two distinct POVs on this subject, and the feeling is pretty intense on both sides. Here are two summaries: Reply to sender: http://www.unicom.com/pw/reply-to-harmful.html Reply to list: http://www.blackgate.net/consulting/reply-to_munging_useful.html IMO, the various purist postions are meaningless drivel by people more concerned with following a ideal notion instead of being concerned with how the software is actually used. If you think in those terms, replies to discussion lists should go to the list, and replies to announcement-type lists should go to the sender. In cases where people are discussing problems and supplying solutions, replying to the list is essential so that as many people as possible can benefit from the knowledge contained in the reply. Private replies only benefit the lone recipient, while list replies benefit everyone on the list and everyone who later searches the archives. # p.d. -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
I think you need to get a database. Anyways, if anything, it should create no more than 5,000 files, since 5,000 facts shouldn't talk about 30,000 animals. There have been a few discussions about looking at files in directories though, if you want to look at those. -- http://mail.python.org/mailman/listinfo/python-list
Re: Web client, https and session management
On 2005-07-12, Yannick Turgeon [EMAIL PROTECTED] wrote: To acheive point #3, which is the goal, my web client has to manage session (because of the login aspect). This is the part I don't know how it's working. You might want to take a look at the ClientCookie package. -- Grant Edwards grante Yow! Then, it's off to at RED CHINA!! visi.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
I will transfer eventually use a database but is there any way for now you could help me make the text files? Thank you so much. Reece -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
I will transfer eventually use a database but is there any way for now you could help me make the text files? Thank you so much. Reece -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
Oh, I seem to have missed the part saying 'or other word'. Are you doing this for every single word in the file? -- http://mail.python.org/mailman/listinfo/python-list
Issues With Threading
Hello All,
I'm having issues capturing the output from a program while using
threading. Program runs ok when I run without threading. Here's my
Python code and the Java class that is called by it.
Python :
#!/usr/bin/python
import popen2
import threading
for id in range( 10 ) :
( err_out, stdin ) = popen2.popen4( ( '/usr/bin/java JavaTest
%s' ) % ( id ) )
for line in err_out.readlines() :
print line,
def test( id ) :
print Called %s % ( id )
( err_out, stdin ) = popen2.popen4( ( '/usr/bin/java JavaTest
%s' ) % ( id ) )
for line in err_out.readlines() :
print line,
#for id in range( 10 ) :
#thread = threading.Thread( target=test, args=( [ id ] ) )
#thread.start()
Java :
import java.util.Date;
public class JavaTest {
public static void main( String args[] ) {
System.out.println( args[0] + - + new
Date().toString() );
}
}
When I run without threading, I get the correct output :
0 - Tue Jul 12 11:33:51 EDT 2005
1 - Tue Jul 12 11:33:52 EDT 2005
2 - Tue Jul 12 11:33:52 EDT 2005
3 - Tue Jul 12 11:33:53 EDT 2005
4 - Tue Jul 12 11:33:53 EDT 2005
5 - Tue Jul 12 11:33:54 EDT 2005
6 - Tue Jul 12 11:33:54 EDT 2005
7 - Tue Jul 12 11:33:54 EDT 2005
8 - Tue Jul 12 11:33:54 EDT 2005
9 - Tue Jul 12 11:33:54 EDT 2005
When I uncomment the threading section and run again, I see that the
function is called, but the result from the Java code does not get
printed :
Called 0
Called 1
Called 2
Called 3
Called 4
Called 5
Called 6
Called 7
Called 8
Called 9
I hope this is just a nuance that I've run across and it's an easy
solution ... any advice pointing me in the right direction would be
greatly appreciated.
Thanks
--
http://mail.python.org/mailman/listinfo/python-list
Re: Help with inverted dictionary
Yes, I am. Does that make it harder. -- http://mail.python.org/mailman/listinfo/python-list
Re: Software needed
Document Management Software is a little vague. What do you want it to do? In general though, when someone says content management and Python, the general response is Zope, usually with Plone on top. -- http://mail.python.org/mailman/listinfo/python-list
automatic form filling
hi, I would like to know how I could automatically fill a (search) form on a web page and download the resulting html page. More precisely I would like to make a program that would automatically fill the Buscador lista 40 (in spanish, sorry) form in the following webpage: http://www.los40.com/actualidad/listas/lista40.html and download the results for several dates (dia/mes/año = day/month/year). I am not sure this is the right place to ask, but I would be very grateful if anybody can help or redirect me to another mailing list... thx jul __ 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
Fwd: Should I use if or try (as a matter of speed)?
I use Delphi in my day job and evaluating and learning Python over the weekends and spare time. This thread has been very enlightening to me. The comments that Joel of Joel on Software makes here http://www.joelonsoftware.com/items/2003/10/13.html was pretty convincing. But I can see from the comments made by various people here that since Python uses Duck typing and encourages typless styles of functions exceptions may actually be the better way to go. But one advise that he gives which I think is of great value and is good practice is Always catch any possible exception that might be thrown by a library I'm using on the same line as it is thrown and deal with it immediately. DarkCowherd -- http://mail.python.org/mailman/listinfo/python-list
Re: append one file to another
On Tue, 12 Jul 2005 07:38:39 -0700, [EMAIL PROTECTED] wrote: Thanks for the nice suggestions! As a side question, you mentioned opening files in binary mode, in case the code needs to run under Windows or cross-platform. What would happen otherwise? Is it an issue of big little endian or some other issue? No, nothing to do with big and little endian issues. It is all to do with the line delimiter, and possibly the end-of-file marker. Windows uses '\r\n' as the line delimiter for text files. (Or is it '\n\r'? I always forget...) Old-style Macintosh used '\r', and (almost) everything else, including new Macs running OS X, uses '\n'. If you open files in text mode, there can be complications due to the different line endings. To be perfectly frank, I only use Python under Linux, so I don't have the foggiest idea of just what Bad Things can happen. I know it is a big problem when using some FTP programs, which have a tendency to destroy binary programs if you upload/download them in text mode. I just did some experiments here, and can't get anything bad to happen. But whatever the problem is, my grand-pappy always told me, open the danged file in binary mode and you can't go wrong. *wink* I have found some discussions here: http://python.active-venture.com/tut/node9.html Windows makes a distinction between text and binary files; the end-of-line characters in text files are automatically altered slightly when data is read or written. This behind-the-scenes modification to file data is fine for ASCII text files, but it'll corrupt binary data like that in JPEGs or .EXE files. Be very careful to use binary mode when reading and writing such files. and here: http://zephyrfalcon.org/labs/python_pitfalls.html This website recommends: Solution: Use the correct flags -- 'r' for text mode (even on Unix), 'rb' for binary mode. but I've never had any problems using 'rb' for text files under Linux. I'm also told that Windows uses ctrl-Z as the end-of-file marker, and if it finds that character in the middle of a text file, it will assume the file has finished and stop reading. But only in text mode, not binary. I don't think that's a problem for Linux. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
