CODEWITHSUNDEEP
pythonfunctionparametersargumentsparameter-passing
Jon Wilcox
Jon Wilcox

Reputation: 51

Avoid having to rewrite function calls whenever parameters change

I frequently write more advanced wrapper functions that call primitive functions I wrote earlier in a module. The point is to re-use code from the primitive function and do something extra but optional. The pain point is whenever I update the primitive function's parameters, I have to adjust for that in the advanced function. Is there a way to make this dynamic through the way the advanced function is written (something like below)? Or is there a better solution in general?

I could just write an all-encompassing general function, but I think it would be a waste of code.

It's usually like the example below but with deeper and deeper nested functions in additional wrappers to add additional optional parameters.

advanced/wrapper function

def pb_jam_sandwich(sandwich, pb, jam=None):
    if jam is None:
        pb_sandwich(sandwich, pb)
    else:
        pb_sandwich(sandwich, pb)
        add_jam(jam)

I was thinking something like this for the advanced function, if it worked:

def pb_jam_sandwich(*args, jam=None):
    if jam is None:
        pb_sandwich(*args)
    else:
        pb_sandwich(*args)
        add_jam(jam)

Upvotes: 0

Views: 119

Answers (1)

chepner
chepner

Reputation: 532208

I think your design is backwards. More specific functions should be defined in terms of more general ones.

# Note: no default values
def pbandjsandwich(pb, sandwich, jam):
    return pb + sandwich + jam

def pbsandwich(pb, sandwich):
    return pbandjsandwich(pb, sandwich, 0)

Now you can ask the question of whether or not you need a separate function pbsandwich at all, or if a default value for jam is sufficient:

def pbandjsandwich(pb, sandwich, jam=0):
    return pb + sandwich + jam

Avoiding a second function call would be more efficient, at least.

Upvotes: 1

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