每次我在Python中调用函数时，都会改变不同的参数

Question

I have a function

def input_definition(parameter_variation=None):

    input_def = {}
    input_def['a'] = 1
    input_def['b'] = 2
    input_def['c'] = 3
    ...
    input_def['z'] = 26

    # Apply the parameter variation by means of the input argument 'parameter_variation'.
    # ...

    # Save 'input_def' to external file with dill module.
    # ...

with many parameters. I want to vary some of these parameters by giving parameter_variation to the function input_definition . I need to vary different parameters each time I call input_definition .

So one time parameter_variation contains values for a and b and another time parameter_variation contains values for c and d .

What is the best / most neat / Pythonic way to do this? Or is it perhaps better to use kwargs?

Answer 1

You can use kwargs for this like so:

def some_func(**kwargs):
    my_dict = dict(
        a=1,
        b=2,
        c=3,
        d=4
    )
    my_dict.update(**kwargs)

This will set your defaults and then override them with kwargs.

It is arguable better to give more limited inputs to the dict by simply using default arguments like so:

def some_func(a=1, b=2, c=3, d=4):
    my_dict = dict(
        a=a,
        b=b,
        c=c,
        d=d
    )

This is more secure and makes your intentions more understandable to someone reading your code. But is less flexible in comparison to kwargs .