Python CTypes translation of (pv != NULL)

p.lavarre at p.lavarre at
Tue Sep 26 15:34:42 EDT 2006

> > > > Q: The C idea of (pv != NULL) ...
> >
> > CTypes tutorial ... == False ... == None ... is None ...
> Generally ... 'if pv: ....'  ... should work.
> Except for c_void_p, c_char_p and c_wchar_p instances.

Please can we give me an example of these exceptions?

Indeed those types are the _p types I use most often. Now here
'bool(pv)' and 'if pv' tell me that null is False and non-null is True,
for every kind of null or non-null that I know how to construct.

Is that mapping somehow not reliable across all instances? Or not

You did mean to say that the Python fragments 'bool(pv)' and 'if pv'
somehow are not accurate translations of the C fragments 'pv != NULL'
and 'if pv'?  Something other kind of Python is?

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