def apply_twice(func, arg): return func(func(arg)) def add_five(x): return x + 5 print(apply_twice(add_five, 10))

Question

Can someone explain this code line and specially
func(func(arg))
How can even exist when it is not even declared

Answer 1

Read how
apply_twice(add_five, 10)>>>
>>>add_five(add_five(10))>>>
>>>add_five(15)>>>
>>>20