Question

When I call

help(Mod.Cls.f) 

(Mod is a C extension module), I get the output

Help on method_descriptor:  f(...)     doc_string

What do I need to do so that the help output is of the form

Help on method f in module Mod:  f(x, y, z)     doc_string

like it is for random.Random.shuffle, for example?

My PyMethodDef entry is currently:

{ 'f', f, METH_VARARGS, 'doc_string' } 

Answer 1

You cannot. The inspect module, which is what ‘pydoc’ and ‘help()’ use, has no way of figuring out what the exact signature of a C function is. The best you can do is what the builtin functions do: include the signature in the first line of the docstring:

>>> help(range) Help on built-in function range in module __builtin__:  range(...)     range([start,] stop[, step]) -> list of integers  ... 

The reason random.shuffle’s docstring looks ‘correct’ is that it isn’t a C function. It’s a function written in Python.