Can anyone explain, why the result was 400 instead of 200?

Question

#source : https://www.geeksforgeeks.org/decorators-in-python/ #Python Decorators

def decor1(func):
    def inner():
        x = func()
        return x * x
    return inner

def decor(func):
    def inner():
        x = func()
        return 2 * x
    return inner

@decor1
@decor
def num():
    return 10

print(num())

Answer 1

It's an expected result,

decor1(decor(num())) # it's call like this.

decor >> return 10 *2 >> 20

decor1 >> return 20 * 20 >> 400

And I would suggest putting the print inside the decorator to identify the execution order.

<function decor at 0x113de8430>
10
<function decor1 at 0x113bfc430>
20
400