On Sun, 10 May 2015 14:12:44 -0500, boB Stepp wrote:
I have to admit being surprised by this, too. I am just now studying on
how to write my own classes in Python, and have come to realize that
doing this is *possible*, but the *surprise* to me is why the language
design allowed this to
On Tue, 12 May 2015 02:35:23 +1000, Steven D'Aprano wrote:
On Mon, 11 May 2015 11:37 pm, Mel Wilson wrote:
On Sun, 10 May 2015 14:12:44 -0500, boB Stepp wrote:
I have to admit being surprised by this, too. I am just now studying
on how to write my own classes in Python, and have come
On Sun, 10 May 2015 13:43:03 -0700, Chris Seberino wrote:
Instead of learning only Scheme or only Python for a one semester intro
course, what about learning BOTH? Maybe that could somehow get the
benefits of both?
I'm thinking that for the VERY beginning, Scheme is the fastest language
On Fri, 08 May 2015 08:40:34 -0700, Tommy C wrote:
I'm trying to apply OOP in this bouncing ball code in order to have
multiple balls bouncing around the screen. The objective of this code is
to create a method called settings, which controls all the settings for
the screen and the bouncing
On Sat, 09 May 2015 03:49:36 +1000, Chris Angelico wrote:
Yes, but can you *distinguish* them in terms of default argument versus
code object creation? How do you know that the function's code object
was created when compile() happened, rather than being created when the
function was defined?
On Sun, 19 Apr 2015 09:03:23 -0700, Rustom Mody wrote:
Now if Thomson and Ritchie (yeah thems the guys) could do it in 1970,
why cant we revamp this 45-year old archaic program=textfile system
today?
Dunno. Why not? There's half of you right there.
--
On Mon, 20 Apr 2015 03:53:08 +1000, Steven D'Aprano wrote:
On Mon, 20 Apr 2015 02:03 am, Rustom Mody wrote:
Well evidently some people did but fortunately their managers did not
interfere.
You are assuming they had managers. University life isn't exactly the
same as corporate culture.
On Wed, 08 Apr 2015 07:56:05 -0700, jonas.thornvall wrote:
There is no need for inventing a new set of characters representing
32-bit numbers. You will not be able to learn them by heart anyway,
unless they build on a interpretation system binaries, decimals.
See Jorge Luis Borges, _Funes the
On Tue, 07 Apr 2015 23:19:49 -0700, jonas.thornvall wrote:
And you have just created 429496729 unique symbols ;), in a pencil
stroke.
No. You did that, when you said base 429496729. Representing the
symbols in a computer is no problem, any Python long int can do that. To
display the
Antti J Ylikoski wrote:
In his legendary book series The Art of Computer Programming,
Professor Donald E. Knuth presents many of his algorithms in the form
that they have been divided in several individual phases, with
instructions to GOTO to another phase interspersed in the text of the
Steven D'Aprano wrote:
On Fri, 16 Mar 2012 17:53:24 +, Neil Cerutti wrote:
On 2012-03-16, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info
wrote:
Ah, perhaps you're talking about *prescriptivist* grammarians, who
insist on applying grammatical rules that exist only in their own
Paul Rubin wrote:
dreamingforw...@gmail.com writes:
hanging out on the Prothon list now and then, at least until we get
the core language sorted out?
Haha, a little late, but consider this a restart.
It wasn't til I saw the word Prothon that I scrolled back and saw you
were responding to
Terry Reedy wrote:
The problem was another subtle bug in the current example:
self.hi_there[text] = Hello,
The spurious comma at the end makes the value of the 'text' attribute a
one-elememt tuple and not just a string. I presume tcl-based tk handles
that in the manner appropriate
Rick Johnson wrote:
I get sick and tired of doing this!!!
if maxlength == UNLIMITED:
allow_passage()
elif len(string) maxlength:
deny_passage()
What Python needs is some constant that can be compared to ANY numeric
type and that constant will ALWAYS be larger!
Easily fixed:
Andrea Crotti wrote:
I have the following very simplified situation
from atexit import register
def goodbye():
print(saying goodbye)
def main():
while True:
var = raw_input(read something)
if __name__ == '__main__':
register(goodbye)
main()
Jabba Laci wrote:
Could someone please tell me what the following sorting algorithm is
called?
Let an array contain the elements a_1, a_2, ..., a_N. Then:
for i in xrange (N-1):
for j in xrange (i, N):
if a[j] a[i]:
a[i], a[j] = a[j], a[i]
It's so simple that
Prasad, Ramit wrote:
for i in xrange (N-1):
for j in xrange (i, N):
if a[j] a[i]:
a[i], a[j] = a[j], a[i]
It's what Wikipedia says a selection sort is: put the least element in
[0], the least of the remaining elements in [1], etc.
If your only requirement to
Den wrote:
I disagree. In a bubble sort, one pointer points to the top element,
while another descents through all the other elements, swapping the
elements at the pointers when necessary.
'When I use a word,' Humpty Dumpty said, in rather a scornful tone, 'it
means just what I choose it to
zigi wrote:
Hello,
M2crypto
__init__(self, alg, key, iv, op, key_as_bytes=0, d='md5',
salt='12345678', i=1, padding=1)
I wont write app, using M2crypto and I can not understand what are the
arguments:
key, iv, op, salt ?
What they do ?
I assume you're reading in
Steven D'Aprano wrote:
A more explicit note will help, but the basic problem applies: how do you
write deterministic tests given that the random.methods (apart from
random.random itself) can be changed without warning?
Biting the bullet would mean supplying your own PRNG, under your control.
Dennis Lee Bieber wrote:
On Wed, 1 Feb 2012 23:25:36 -0800 (PST), oleg korenevich
void.of.t...@gmail.com wrote:
Thanks for help. In first case all vars is python integers, maybe
math.floor is redundant, but i'm afraid that same error with math
module call will occur in other places of app,
Dave Angel wrote:
I tried your experiment using Python 2.7 and Linux 11.04
def f(a):
from math import sin, cos
return sin(a) + cos(a)
print f(45)
Does what you needed, and neatly. The only name added to the global
namspace is f, of type function.
I was a bit surprised
Charles Yeomans wrote:
To catch more than one exception type in an except block, one writes
except (A, B, C) as e:
I'm wondering why it was decided to match tuples, but not lists:
except [A, B, C] as e:
The latter makes more sense semantically to me -- catch all exception
types in a
Chris Angelico wrote:
On Wed, Feb 1, 2012 at 9:03 AM, Duncan Booth
duncan.booth@invalid.invalid wrote:
Abitrarily nested tuples of exceptions cannot contain loops so the code
simply needs to walk through the tuples until it finds a match.
Is this absolutely guaranteed? The C API for
Charles Yeomans wrote:
To catch more than one exception type in an except block, one writes
except (A, B, C) as e:
I'm wondering why it was decided to match tuples, but not lists:
except [A, B, C] as e:
The latter makes more sense semantically to me -- catch all exception
types in a
Jean-Michel Pichavant wrote:
isinstance is fine, if you could find the source where it is
discouraged... Could be a consequence of some specific context.
However, checking types in OOP is in general a failure. Unitary tests
are possibly an exception.
I think it's discouraged when people try
Adam Funk wrote:
(Warning: this question obviously reflects the fact that I am more
accustomed to using Java than Python.)
Suppose I'm creating a class that represents a bearing or azimuth,
created either from a string of traditional bearing notation
(N24d30mE) or from a number indicating
Steven D'Aprano wrote:
On Fri, 23 Dec 2011 13:13:38 +, Neil Cerutti wrote:
On 2011-12-23, Neil Cerutti ne...@norwich.edu wrote:
...you know, assuming it wouldn't break existing code. ;)
It will. Python's default argument strategy has been in use for 20 years.
Some code will rely on it.
Chris Angelico wrote:
On Fri, Dec 23, 2011 at 1:13 AM, Hans Mulder han...@xs4all.nl wrote:
How about:
class name=MyClass superclasses=A, B, C
...
/class
More more readable! And it's a standard!
Unfortunately it's not Pythonic, because indentation is insignificant.
Easy-peasy:
Chris Angelico wrote:
It's no more strange than the way some people omit the u from colour. :)
Bonum Petronio Arbiteri, bonum mihi.
Mel.
--
http://mail.python.org/mailman/listinfo/python-list
Tim wrote:
Hi, I need to generate a list of file names that increment, like
this:
fname1
fname2
fname3 and so on.
I don't know how many I'll need until runtime so I figure a
generator is
called for.
def fname_gen(stem):
i = 0
while True:
i = i+1
yield
GZ wrote:
Here is my situation. A parent object owns a list of files (or other
objects with a close() method). The close() method can sometimes
fail
and raise an exception. When the parent object's close() method is
called, it needs to close down as many files it owns as possible,
even
if
candide wrote:
First, could you confirm the following syntax
import foo as f
equivalent to
import foo
f = foo
Now, I was wondering about the usefulness in everyday programming of
the
as syntax within an import statement. [ ... ]
It gives you an out in a case like
Python
Vyacheslav Maslov wrote:
So, the main question is why using syntax like [X] python constuct list
with
one item, but when i try to construct tuple with one item using similar
syntax (X) python do nothing?
Because `(` and `)` are used in expressions to bracket sub-expressions.
a = (4 + 3) *
John Nagle wrote:
True, False, and None should be reserved words in Python.
None already is.
The permissiveness makes it less painful to upgrade to new versions of
Python. True and False only recently got assigned conventional
values, but you can still import old modules without
Neil Cerutti wrote:
The interpreter explains it: A list is not a hashable object.
Choosing a hash table instead of some kind of balanced tree seems
to be just an optimization. ;)
Even with a balanced tree, if a key in a node changes value, you may
have to re-balance the tree. Nothing in a
[EMAIL PROTECTED] wrote:
Howdy, a (possibly) quick question for anyone willing to listen.
I have a question regarding lists and Classes; I have a class called
gazelle with several attributes (color, position, etc.) and I need
to create a herd of them. I want to simulate motion of individual
jamadagni wrote:
OK fine. It is clear that this feature must be implemented if at all
only on a per-module basis. So can we have votes for per-module
implementation of this feature?
The only way that can work is if the API to the module doesn't expose
ANY sequence indices. It would be a
[EMAIL PROTECTED] wrote:
In Visual Basic there is the keyword with which allows an object-
name to be declared as governing the following statements. For
example:
with quitCommandButton
.enabled = true
.default = true
end with
This is syntactic sugar for:
Scott wrote:
Now I read somewhere that you could change the list inside that tupple. But
I can't find any documentation that describes HOW to do it. The only things
I CAN find on the subject say, Don't do it because its more trouble than
it's worth. But that doesn't matter to me, because
7stud wrote:
On Apr 7, 8:27 am, Carsten Haese [EMAIL PROTECTED] wrote:
Adding useless features always makes a product worse. What's your use
case for tuple.index?
I'll trade you an index method for tuples for the whole complex number
facility.
Actually, I've found the use cases for
Peter Otten wrote:
Lucas Malor wrote:
Hello all. I'm trying to do a little script. Simply I want to make a list
of all options with them default values. If the option is not specified in
the command line, the script must try to read it in a config.ini file. If
it's not present also there,
bahoo wrote:
[ ... ]
Thanks, this helped a lot.
I am now using the suggested
map(str.strip, open('source.txt').readlines())
However, I am a C programmer, and I have a bit difficulty
understanding the syntax.
I don't see where the str came from, so perhaps the output of
Terry Reedy wrote:
Tim Roberts [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
| Once upon a time,
| Basic enthusiasts would have used the word tokenized to describe .pyc
files.
Perhaps, but they would, I think, have been wrong. Tokenized Basic to the
best of my knowledge,
belinda thom wrote:
On Mar 23, 2007, at 11:04 AM, [EMAIL PROTECTED] wrote:
On Mar 23, 12:52 pm, belinda thom [EMAIL PROTECTED] wrote:
Hi,
I'm writing a function that polls the user for keyboard input,
looping until it has determined that the user has entered a valid
string of characters,
Qilong Ren wrote:
Hi, Shane,
Thanks for fast reply.
What I used is :
for line in open(FILE):
do stuff
I don't want to store all lines in a list because sometimes the file is very
large. We need to store the value of the previous line in a variable. Is that
right?
Gerard Flanagan wrote:
On Mar 9, 4:17 pm, cesco [EMAIL PROTECTED] wrote:
On Mar 9, 3:51 pm, Paul Rubin http://[EMAIL PROTECTED] wrote:
cesco [EMAIL PROTECTED] writes:
I have to generate a list of N random numbers (integer) whose sum is
equal to M. If, for example, I have to generate 5 random
for
oracles, where a computation would be allowed to call out
sometimes to a non-computational process to obtain some
required result. Used maybe by interactive debugging programs.
Cheers,Mel.
Mel Wilson wrote:
[ ... ]
Douglas Hofstadter's _Goedel, Escher, Bach: an Eternal Golden
Terry Reedy wrote:
James J. Besemer [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
I propose that we extend the semantics of print such that if the object
to
be printed is a generator then print would iterate over the resulting
sequence of sub-objects and recursively print each
sam wrote:
tomer:
It is my opinion that you would loose performance if the Python
interpreter had the additional task of verifying byte code. It might be
more appropriate to have a preprocessor that did the verifying as it
compiled the byte code.
Possibly. A good book on the topic is
John Salerno wrote:
Hi all. Quick question (but aren't they all?) :)
Do you think it's a good idea to use the 'from name import *'
statement when using a GUI module? It seems on wxPython's site, they
recommend using import wx nowadays, but I wonder if that advice is
followed. Also, I'm
[EMAIL PROTECTED] wrote:
Lonnie List comprehensions appear to store their temporary result in a
Lonnie variable named _[1] (or presumably _[2], _[3] etc for
Lonnie nested comprehensions)
Known issue. Fixed in generator comprehensions. Dunno about plans to fix
it in list
Paul Rubin wrote:
Paul Du Bois [EMAIL PROTECTED] writes:
The second is that you don't like the late-binding behavior of
generator expressions. PEP 289 has this to say:
After much discussion, it was decided that the first (outermost)
for-expression should be evaluated immediately and that the
[EMAIL PROTECTED] wrote:
Hello all.
On page 479, the 2nd edition of the Learning Python book, this code
appears
class Derived(Base):
def __init__(self, arg, *args, **kw):
self.__init__(self, *args, **kw)
Surely self.__init__ should be
[EMAIL PROTECTED] wrote:
The original post only mentions deleting the values in the list, not
the list itself. Given that you want to keep the list and just ditch
the values it contains I'd go with:
list1 = []
Depends what you mean by keep the list. Consider
class C (object):
def
Alex Pavluck wrote:
Hello. On page 124 of Thinking like a Computer Scientist. There is
an exercise to take the following code and with the use of TRY: /
EXCEPT: handle the error. Can somone help me out? Here is the code:
[ ... ]
What error?
Python 2.4.2 (#1, Jan 23 2006, 21:24:54)
[GCC
[EMAIL PROTECTED] wrote:
Consider this example:
X = range(5)
Y = iter(X)
Z = iter(Y)
As you can see, X is a container, and Y is an iterator.
They are simliar in that iter works on them both.
Cristoph claims that this causes confusion.
Why? Because iter doesn't have the same meaning
John D Salt wrote:
Mel Wilson [EMAIL PROTECTED] wrote in news:_s2bg.8867$aa4.296233
@news20.bellglobal.com:
[Snips]
Just reinforces the central truth. The mascot doesn't
*have* a name. Most things don't.
Most things don't have names?
I'll believe you if you can give me a list
of wrote:
a = 1+3j
complex(str(a))
Why does this not work ? It should
It would be nice.
Looks like str(1+3j) is returning an expression in string
form. Maybe there is no actual complex literal.
eval (str(1+3j)) works.
Python 2.4.2 (#1, Jan 23 2006, 21:24:54) [GCC 3.3.4] on linux2
Type
Steve wrote:
Carl J. Van Arsdall wrote:
John D Salt wrote:
hon-list/2003-September/185612.html
Odi must be the Dutch for Monty.
Nope. If it was Dutch it would probably be Odie
Damn.
Odi(e) was a punk. I'm gonna be a rebel without a cause and stay with
Monty ;)
Yes ! Monty sounds
Tim Chase wrote:
compboy wrote:
How do you print elements of the list in one line?
alist = [1, 2, 5, 10, 15]
so it will be like this:
1, 2, 5, 10, 15
print ', '.join(alist)
1, 2, 5, 10, 15
???
Python 2.4.2 (#1, Jan 23 2006, 21:24:54)
[GCC 3.3.4] on linux2
Type help, copyright,
vdrab wrote:
I guess the take-away lesson is to steer clear from any reliance on
object identity checks, if at all possible. Are there any other such
optimizations one should like to know about?
Object identity checks are just the thing/numero uno/ichiban
for checking object identity. A
Roger Miller wrote:
Steve R. Hastings wrote:
a = 0
b = 0
a is b # always true
Is this guaranteed by the Python specification, or is it an artifact of
the current implementation?
AFAIK it's an artifact. The performance hit it Python
stopped sharing small integers could be enormous,
[EMAIL PROTECTED] wrote:
Hello,
I need your help understanding lambda (and doing it a better way
without).
f = lambda x : x*x
[ ... ]
# the idea is now to give the definition of the multiplication of
functions and integers
# (f * c)(xx) := f(x)*c
[lambda xx: f(xx)*y for y in
Anthony Liu wrote:
I am at my wit's end.
I want to generate a certain number of random numbers.
This is easy, I can repeatedly do uniform(0, 1) for
example.
But, I want the random numbers just generated sum up
to 1 .
I am not sure how to do this. Any idea? Thanks.
numbers.append
Alan Morgan wrote:
In article [EMAIL PROTECTED],
Raymond Hettinger [EMAIL PROTECTED] wrote:
* s.clear() is more obvious in intent
Serious question: Should it work more like s=[] or more like
s[:]=[]. I'm assuming the latter, but the fact that there is
a difference is an argument for not
Steven D'Aprano wrote:
Convenience and obviousness are important for APIs -- that's why lists
have pop, extend and remove methods. The only difference I can see between
a hypothetical clear and these is that clear can be replaced with a
one-liner, while the others need at least two, e.g. for
Ville Vainio wrote:
Fredrik Lundh wrote:
because Python already has a perfectly valid way to clear a list,
perhaps ?
del l[:]
Ok. That's pretty non-obvious but now that I've seen it I'll probably
remember it. I did a stupid while l: l.pop() loop myself.
Actually, it's in the Library
John Salerno wrote:
Christoph Haas wrote:
L[2:2]=[3]
[ ... ]
What if you wanted to insert an actual list into that
slot? Would
you have to wrap it in double brackets?
Yep.
It's a strong-typing thing. Slices of lists are lists, and
therefore what you assign to one has got to be a list, or
James Stroud wrote:
Fredrik Lundh wrote:
James Stroud wrote:
Perhaps you did not know that you can inheret directly from dict, which
is the same as {}. For instance:
class Dict({}):
pass
I must have been hallucinating. I swear I did this before and it worked
just like class
Fredrik Lundh wrote:
(del doesn't work on dictionaries)
... or rather [:] doesn't work on dictionaries ...
Python 2.4.2 (#1, Jan 23 2006, 21:24:54)
[GCC 3.3.4] on linux2
Type help, copyright, credits or license for more information.
d={'a':1, 'b':2, 'c':3}
print d
{'a': 1, 'c': 3, 'b': 2}
py wrote:
Say I have...
x = 132.00
but I'd like to display it to be 132 ...dropping the trailing
zeros...
print '%g' % (float(x),)
might work.
Mel.
--
http://mail.python.org/mailman/listinfo/python-list
In article [EMAIL PROTECTED],
Christian Ergh [EMAIL PROTECTED] wrote:
Ah, ok, i misunderstood you. Well, to mark it as a syntax error sounds
good, and at the Moment I would not know a case where this conflicts
with a implementation.
Well, you can overload prefix `+` and `-` operators on an
In article [EMAIL PROTECTED],
houbahop d.lapasset[Remove me)@chello.fr wrote:
Thank you everyone, but I still not understand why such a comon feature like
passing parameters byref that is present in most serious programming
languages is not possible in a clean way,here in python.
I have the habit
In article [EMAIL PROTECTED],
Peter Otten [EMAIL PROTECTED] wrote:
Mel Wilson wrote:
The thing is, that once you drop local-namespace
optimization, the entire function gets slowed down, possibly
by 40%:
It's not that bad as most of the extra time is spend on compiling the
string.
[ ... ]
def
In article [EMAIL PROTECTED],
Steven Bethard [EMAIL PROTECTED] wrote:
Jeff Shannon wrote:
I was referring to functions which have an internal exec statement, not
functions which are created entirely within an exec -- i.e., something
like this:
Thanks for the clarification. Here's the results
In article [EMAIL PROTECTED],
Steven Bethard [EMAIL PROTECTED] wrote:
I believe what Peter Otten was pointing out is that calling __eq__ is
not the same as using ==, presumably because the code for == checks the
types of the two objects and returns False if they're different before
the __eq__ code
77 matches
Mail list logo
