use a class instance to make a decorator

using_a_class_instance_as_a_decorator.py

# Write a tracer decorator
class Tracer():
    def __init__(self):
        pass
    
    def __call__(self, f):
        def wrapper(*args, **kwargs):
            print('Called function %s' % f.__name__)
            return f(*args, **kwargs)
        return wrapper
    
tracer = Tracer()
tracer

@tracer
def rotate(list_):
    rotated = [list_[-1]] + list_[0:-1]
    print(rotated)
    if rotated[-1] != 0:
        rotate(rotated)

my_list = list(range(0,6))
rotate(my_list)