How to override original signature of a function in python

Question

Let's say I have the following function:

def person(*args, **kwargs):
    '''
       person(name, age, parents=2)
       this is a docstring.
    '''

If I execute help(person) I would get

person(*args, **kwargs)
    person(name, age, children=5)
    this is a docstring.

But instead, I want to see:

person(name, age, children=5)
    this is a docstring.

Please provide more information. E.g., what is "the documentation"? — Jan Stránský, Aug 19 '20 at 14:03
are you looking for [functools.partial](https://docs.python.org/3.8/library/functools.html#functools.partial)? — FObersteiner, Aug 19 '20 at 14:07
@MrFuppes can you use it to override the function signature? (or hide it) — Tomergt45, Aug 19 '20 at 14:08
So modifying existing docstring? something like [this](https://stackoverflow.com/questions/4056983/how-do-i-programmatically-set-the-docstring)? — Jan Stránský, Aug 19 '20 at 14:09
Or simply adding a function docstring as proposed by Yeji Ha? — Jan Stránský, Aug 19 '20 at 14:10

score 1 · Answer 1 · answered Aug 19 '20 at 14:15

1

You can simply overwrite .__doc__ attribute:

def a():
    """orig docstring"""
    pass
help(a)
a.__doc__ = """modified docstring"""
help(a)

answered Aug 19 '20 at 14:15

Jan Stránský

1,671
1
11
15

I tried to edit my question to make it a bit more clear. My question is not how to set the docstring of the function but rather changing the signature (i.e. when calling `help(person)` I don't want to see `person(*args, **kwargs)` but rather `person(name, age, parents=2)` ONLY. – Tomergt45 Aug 19 '20 at 14:21

score 0 · Answer 2 · edited Aug 19 '20 at 14:12

0

You could always use docstrings, like this:

def function(...):
    """
    This function does this and that. The parameters are the following:
    param1 = ...
    param2 = ...
    ...
    """
    # code

Then you can simply call the .doc method and it prints out the docstring. It works like this:

    print.__doc__

Or for better readability:

    import pprint
    pprint.pprint(pprint.__doc__, indent=4)

Pprint is pretty print.

edited Aug 19 '20 at 14:12

Jan Stránský

1,671
1
11
15

answered Aug 19 '20 at 14:07

Yeji Ha

86
6

This is not what I asked. I asked how you can override the original signature of a function, for example, if you press `shift+tab` to see the doc of a function in jupyter notebook you will be presented with the function signature and doc string, what I want is to either override the function signature or hide it. – Tomergt45 Aug 19 '20 at 14:12
1

"This is not what I asked" - as you see from this answer and also the discussion below OP, it is not really clear what you have asked.. – Jan Stránský Aug 19 '20 at 14:13
To be honest, your question was rather vague. To my knowledge, overriding (as in C++) is not possible in Python. – Yeji Ha Aug 19 '20 at 14:13
Excuse me if wasn't clear enough, I am trying to achieve something like in [this](https://stackoverflow.com/questions/12082570/override-function-declaration-in-autodoc-for-sphinx/12087750#12087750) answer but it doesn't seem to work for me, hence my question. – Tomergt45 Aug 19 '20 at 14:14

How to override original signature of a function in python

2 Answers2