Inner Functions captures outside variable?

Question

def outer_function(some_function):
    def inner_function(arg):
        print arg
    return inner_function

def function_2(a):
    return a

x = outer_function(function_2)
x(3)

My issue here is that how is inner_function able to capture the argument which I passed to x which is 3. How is the inner function able to capture an outside function argument?

Answer 1

The inner function isn't capturing an outer function argument.

x = outer_function(function_2)

x is now a reference to inner_function, which takes in an argument and prints it.

x(3)

This is the same as inner_function(3), which just prints 3 so 3 is printed.