On 2/24/2015 8:56 PM, Gregory P. Smith wrote:
> inspect.getargspec(method) and inspect.signature(method) both include
> the 'self' parameter but how are we to figure out from method itself
> that it is actually bound and that its first parameter is expected to be
> a bound instance?
>
> So far I've come up with:
> /inspect.ismethod(method) or inspect.ismethoddescriptor(method)/
>
> But that is still not quite right as it remains False in 3.4 for the
> simple case of:
>
>>>> class A:
> ... def x(self):
> ... pass
> ...
>>>> inspect.ismethod(A.x)
> False
>>>> inspect.ismethoddescriptor(A.x)
> False
>>>> inspect.signature(A.x).parameters
> mappingproxy(OrderedDict([('self', <Parameter at 0x7fdd8188eae8 'self'>)]))
>>>> inspect.getargspec(A.x)
> ArgSpec(args=['self'], varargs=None, keywords=None, defaults=None)
>
> The above works if use it on object.__init__, but not on a method of an
> uninstantiated class. (it also works on the instantiated A().x)
>
> Checking if /(inspect.isfunction(method) and method.__qualname__ !=
> method.__name__)/ perhaps but that seems questionably hacky. Is there a
> right way to do this via the inspect module that I've missed?
>
> It seems like that'd be nice, but I don't feel like I know enough to
> write up a feature request for it yet. (granted I hope nobody /wants/
> to write code that does this...)
I'm not sure if it's correct, but deep in a library of mine I have:
elif type(fn) == types.MethodType:
# bound method?
if fn.im_self is None:
# no 'self'
nskip = 0
else:
# need to supply 'self'
nskip = 1
This is also a 2.x library. No idea if it works with 3.x.
Eric.
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