Writing a small function inside a class method[Python]

Question

If I have a script like:

class ClassA(object):
    ...
    def methodA(...):
        varA=...

        def funcA(...):
            ...

        varA=funA(...)

I mean I intend to write a small function inside a class method, which is only used inside this class method. Is this code style OK? I think it's a little ugly. Is there alternate?

One potential problem is that you'll be re-defining `funcA` every time `methodA` is called. — Blender, Dec 21 '12 at 06:55
Why are you doing it this way? Do you have a reason for putting funcA inside `methodA` instead of elsewhere (or just doing its operations directly in the body of `methodA`)? — BrenBarn, Dec 21 '12 at 07:02
@BrenBarn because in this way it seems clearer that funA only works for methodA — ThunderEX, Dec 21 '12 at 07:07
@ThunderEX: But then what is the point of making it a function? Why not just put its contents directly into `methodA`? — BrenBarn, Dec 21 '12 at 07:13
@BrenBarn Because that piece of code is frequently used in the method — ThunderEX, Dec 21 '12 at 07:17
See [this question](http://stackoverflow.com/questions/13984818/limit-a-method-to-be-called-only-through-another-method/13984872#13984872) from just an hour ago for some discussion. — BrenBarn, Dec 21 '12 at 07:19
@ThunderEX, I would only do this if the function really does need to be nested, e.g. if it accesses some variables from the scope of the enclosing method, or if you need different defaults each time (though `partial` may be preferable in the second instance). However, in that situation it is perfectly fine. Don't worry about redefining the function every time the method is called: function definitions are no more expensive than any other object creation. — Duncan, Dec 21 '12 at 09:52

score 1 · Accepted Answer · answered Dec 21 '12 at 07:00

Beauty is in the eye of the beholder.

It is totally fine having a very "local" function nested inside another function - especially from the point of readability of code.

Others will argue with coding style and best practice.

It is your code and you must feel fine with your code in order to understand and read it later.

So if it is fine for you and your understanding of "nice" code, go ahead.

Writing a small function inside a class method[Python]

1 Answers1