Improve ParameterizedFunction signature information

[philippjfr]

When trying to inspect the signature of a ParameterizedFunction I usually want to see the arguments as well as the parameters. However currently the signature only shows the parameters and lists *args and **kwargs in the signature. Here's an example from the datashader circular_layout function:

Init signature: circular_layout(*args, **params)
Docstring:     
params(seed=Integer, uniform=Boolean, name=String)

This gives me no indication that the function expects nodes and edges as arguments.

[jlstevens]

Might be possible to improve the signature but I suspect it would need some more inspect hackery.

[jbednar]

That's strange; the signature is declared as:

def __call__(self, nodes, edges, **params):
   ...

I.e., it's not declaring *args, so why would it show up as *args?

[ceball]

When trying to inspect the signature of a ParameterizedFunction

I'm not sure what you mean by "inspect": could you clarify how you are inspecting?

[philippjfr]

By pressing tab after ParameterizedFunction( in the notebook or typing ParameterizedFunction? in IPython.

[jbednar]

This still seems to be an issue for from datashader.layout import circular_layout, whether using help(circular_layout) or circular_layout? in a notebook; none of them show that *args is supposed to be nodes, edges=None.

[jlstevens]

At this point I want to remove the docstring approach to tab-completion and only support the signature approach.