Chaining decorators result is confusing me
Question:
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())
Can someone explain why the result is 400?
Is it because inner is being returned twice?
I’m learning chaining decorators but it’s a bit confusing at first glance.
Answers:
The num function returns 10, which is then passed to decor (one level higher) in variable x (note that func() refers to num(), hence it returns 10). x is multiplied by 2, yielding 20. The 20 is passed to decor1 (another level higher) in variable x and is multiplied by itself, so 20 times 20 yields 400.
The first decorator applied is @decor, so at this stage your num function will return 2*10.
Then @decor1 is applied so in the end num returns (2*10)*(2*10) which is 400.
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())
Can someone explain why the result is 400?
Is it because inner is being returned twice?
I’m learning chaining decorators but it’s a bit confusing at first glance.
The num function returns 10, which is then passed to decor (one level higher) in variable x (note that func() refers to num(), hence it returns 10). x is multiplied by 2, yielding 20. The 20 is passed to decor1 (another level higher) in variable x and is multiplied by itself, so 20 times 20 yields 400.
The first decorator applied is @decor, so at this stage your num function will return 2*10.
Then @decor1 is applied so in the end num returns (2*10)*(2*10) which is 400.