On 08/03/2011 03:36 AM, Katriel Cohn-Gordon wrote:
On Wed, Aug 3, 2011 at 9:25 AM, Steven D'Aprano wrote:
a, b, c, d, e = [dict() for i in range(5)]
I think this is good code -- if you want five different dicts,
then you should call dict five times. Otherwise Python will
magically call your expression more than once, which isn't
very nice. And what if your datatype constructor has
side-effects?
If the side-effects are correct behavior (perhaps opening files,
network connections, or even updating a class variable) then
constructor side-effects are just doing what they're supposed to.
E.g. something I use somewhat regularly in my code[*]:
a,b,c,d = (file('file%i.txt', 'w') for i in range(4))
If the side-effects aren't performing the correct behavior, fix
the constructor. :)
-tkc
[*] okay, it's more like
(features,
adjustments,
internet,
) = (file(fname) for fname in (
'features.txt',
'adjustments.txt',
'internet.txt'
)
or even
(features,
adjustments,
internet,
) = (
set(
line.strip().upper()
for line
in file(fname)
if line.strip()
)
for fname in (
'features.txt',
'adjustments.txt',
'internet.txt'
)
to load various set() data from text-files.
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