Paul Rubin wrote:
Ethan Furman writes:
Or if any(p for p in [header, body, footer, whatever, ...])
No need for the genexp:
if any([header, body, footer, whatever, ...])
But, you are using the built-in bool cast either way.
Right you are -- and
if any([header, body, footer, whateve
Ethan Furman writes:
> Or if any(p for p in [header, body, footer, whatever, ...])
No need for the genexp:
if any([header, body, footer, whatever, ...])
But, you are using the built-in bool cast either way.
--
http://mail.python.org/mailman/listinfo/python-list
Steven D'Aprano wrote:
On Fri, 17 Jul 2009 16:09:03 +0100, MRAB wrote:
Python did always have True and False.
Oops! I meant "didn't", of course.
$ python1.5
Python 1.5.2 (#1, Apr 1 2009, 22:55:54) [GCC 4.1.2 20070925 (Red Hat
4.1.2-27)] on linux2
Copyright 1991-1995 Stichting Mathematis
Steven D'Aprano writes:
> Since I haven't specified an implementation for assemble_page, it could
> be doing *anything*. Perhaps it has to talk to a remote database over a
> slow link, perhaps it generates 300 lines of really inefficient HTML code
> with no content, perhaps it sends a print job
Paul Rubin wrote:
Steven D'Aprano writes:
def assemble_page(header, body, footer):
if header or body or footer:
do_lots_of_expensive_processing()
else:
do_nothing_gracefully()
Why should the processing be expensive if all three fields are empty?
if header or body o
On Fri, 17 Jul 2009 16:09:03 +0100, MRAB wrote:
> Python did always have True and False.
$ python1.5
Python 1.5.2 (#1, Apr 1 2009, 22:55:54) [GCC 4.1.2 20070925 (Red Hat
4.1.2-27)] on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> True, False
Traceback (innermost last
On Fri, Jul 17, 2009 at 11:09 AM, MRAB wrote:
> Python did always have True and False.
Only if "always" means "since python 2.2.1".
See: http://www.python.org/doc/2.3/whatsnew/section-bool.html and
http://www.python.org/dev/peps/pep-0285/ for details.
--
Jerry
--
http://mail.python.org/mailma
koranthala wrote:
That test was designed to treat None as a boolean False, without
noticing that numeric 0 is also treated as False and could make the
test do the wrong thing. This is an extremely common type of error.
Actually, I felt that 0 not being considered False would be a better
option
On Fri, 17 Jul 2009 07:12:51 -0700, Paul Rubin wrote:
> Steven D'Aprano writes:
>> def assemble_page(header, body, footer):
>> if header or body or footer:
>> do_lots_of_expensive_processing()
>> else:
>> do_nothing_gracefully()
>
> Why should the processing be expensive
Steven D'Aprano writes:
> def assemble_page(header, body, footer):
> if header or body or footer:
> do_lots_of_expensive_processing()
> else:
> do_nothing_gracefully()
Why should the processing be expensive if all three fields are empty?
> if header or body or footer:
On Fri, 17 Jul 2009 00:34:00 -0700, Paul Rubin wrote:
> Steven D'Aprano writes:
>> It is very useful to be able to write e.g.:
>>
>> if header or body or footer:
>> print assemble_page(header, body, footer)
>>
>> and have empty strings to be equivalent to False.
>
> Why doesn't assemble_pag
Steven D'Aprano writes:
> It is very useful to be able to write e.g.:
> if header or body or footer:
> print assemble_page(header, body, footer)
> and have empty strings to be equivalent to False.
Why doesn't assemble_page properly handle the case where header, body,
and footer are all empty?
On Thu, 16 Jul 2009 23:13:51 -0700, koranthala wrote:
>> That test was designed to treat None as a boolean False, without
>> noticing that numeric 0 is also treated as False and could make the
>> test do the wrong thing. This is an extremely common type of error.
>
> Actually, I felt that 0 not
On Thu, Jul 16, 2009 at 11:13 PM, koranthala wrote:
>> That test was designed to treat None as a boolean False, without
>> noticing that numeric 0 is also treated as False and could make the
>> test do the wrong thing. This is an extremely common type of error.
>
> Actually, I felt that 0 not bein
> That test was designed to treat None as a boolean False, without
> noticing that numeric 0 is also treated as False and could make the
> test do the wrong thing. This is an extremely common type of error.
Actually, I felt that 0 not being considered False would be a better
option.
I had lot of
Albert van der Horst wrote:
Einstein introduced the summation convention for indices that
are used twice. Leaving out summation signs is absolutely hideous,
but it has saved generations of physicists of loosing track (and
their minds.)
There is a joke among mathematicians that if Einstein hadn'
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