Python decorators simple explanation

decorator.py

def decor(func):
    def wrapped(a, b):
        a = 'deco'
        b = 'rated'
        return func(a, b)
    return wrapped  # not calling yet


@decor  # init decor here
def funkcia(a, b):
    return a + b

a = 1
b = 2

print(funkcia(a, b))
# 'decorated'