comparison with None
steve at holdenweb.com
Thu Apr 19 14:18:30 CEST 2007
Steven Howe wrote:
> Alan Isaac wrote: [type comparison stuff]
> I love scripting languages ... but sometimes an explicit evaluation that
> one would find in
> a compiled language is better.
"better" in what sense?
> Which is why I suggested using the explicit type(x) == types.NoneType as
> opposed to
> x is None
This seems to go entirely against the spirit of the language. It's about
as sensible as writing
(3 > 4) == True
The language *guarantees* that there is only one instance of
types.NoneType, so why not just test for it directly? Among other things
this avoids the need for an explicit import of the types library just so
you can access the namespace.
For extra marks, please explain why you prefer
type(x) == type(None) # or types.NoneType
type(x) is type(None)
The canonical test is, as has already been explained,
x is None
and to use anything else hinders the readability of your code.
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