On 07 May 2011 02:51:50 GMT, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: : On Fri, 06 May 2011 14:57:21 -0700, scattered wrote: : : > is there any problem with : > : > (3) if li == []: : > : > ? : > : > Seems to work when I test it and seems to clearly test what you are : > trying to test. The only problem might be if in some contexts == has the : > semantics of checking for object identity. : : Yes, if li == [] works too. But how do you know li is a list and not some : other sequence type?
It says so in the Subject header :-) : The advantage of the "if x" test is that it is independent of the type of : x. Sure, but the question wasn't ... The problem with 'if x' is that it requires a much more detailed understanding of python. li == [] is as explicit as it gets, and leaves no room for doubt. len(li) == 0 is almost as explicit and much more flexible. Just x is as generic as it gets, but depends on python's convolved rules for duck processing and if you aim at legibility it is better avoided. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
