Python封闭函数

Question

I am learning enclosing functions, and have the following code:

def parent(x="Hello"):
    text = x

    def son():
        print(text)

    return son

print(parent())

Why does print(parent()) does not print "Hello", but rather prints <function parent.<locals>.son at 0x00000136A32E9EA0> ?

I noticed that if I do the following, it will print "Hello":

def parent(x="Hello"):
    text = x

    def son():
        print(text)

    return son

akin = parent()
akin()

What would be the difference between one and another?

Answer 1

Function parent returns another function. That function must be called to take effect:

print(parent()())

Or, to emphasize the calling sequence:

print((parent())()

Answer 2

Here you need to return son()

def parent(x="Hello"):
    text = x

    def son():
        print(text)

    return son # return son()

print(parent())

Here you get difference result ,because are referring akin()

def parent(x="Hello"):
    text = x

    def son():
        print(text)

    return son

akin = parent()
akin() # print(akin) will get the same output of first program

Difference is every function a have memory address, you referring a function without parenthesises () will return address of the function . So in your first program your returning the memory address of the function so you can access the content using parent()() or return the actual value from the function instead of returning address