How does Python run inner functions?

Asked Jul 12 '17 at 01:40

Active Jul 12 '17 at 01:54

Viewed 47 times

I am having difficulties in understanding on how inner functions are run in Python. Please have a look at the following snipped of code:

def f(a, b):
    return a + b

def outer(f):
    def inner(x, y):
        if not isinstance(x, int) and not isinstance(y, int):
            raise TypeError('Please provide integer for both arguments')
        return f(x, y)
    return inner

I am just confused about when inner is run and how it returns the function f with inner 's arguments and lastly the return of inner is returning the f.

Can anyone enlighten the way Python interprets the steps when the above code is passed to the interpreter.

edited Jul 12 '17 at 01:54

asked Jul 12 '17 at 01:40

Dilshad Abduwali

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Your indentation appears to be off. – BrenBarn Jul 12 '17 at 01:41
3

In the code you provided, `inner` is never run. And unless your indentation is off, `inner` doesn't return anything. – Carcigenicate Jul 12 '17 at 01:41
The indentation is fixed now. I'd like to have step by step explanation of how the program runs – Dilshad Abduwali Jul 12 '17 at 02:00
In particular, see the answer [here](https://stackoverflow.com/a/18287297/5014455) and [this very extensive answer](https://stackoverflow.com/a/1594484/5014455) – juanpa.arrivillaga Jul 12 '17 at 02:01
Also, note, the program you have above simply defines two functions, and never calls a single function. So the answer to "when is `inner` run" is *never*. – juanpa.arrivillaga Jul 12 '17 at 02:01

How does Python run inner functions?

0 Answers0