Difference between function and class decorators

# testing decorator functions
def decorator1(func):

    def inner(value):
        print(value)
        inner.history = []
        inner.history.append(value)

    return inner


@decorator1
def test1(value):
    pass

print("Testing function decorators")
test1(1)
test1(2)
print(test1.history)

# testing class functions
class Decorator2(object):
    def __init__(self, func):
        self._func = func
        self.history = []

    def __call__(self, value):
        print(value)
        self.history.append(value)


@Decorator2
def test2(value):
    pass

@Decorator2
def test3(value):
    pass


print("Testing class decorators")
test2(1)
test2(2)
test3(3)
print(test2.history)

"""
Testing function decorators
1
2
[2]
Testing class decorators
1
2
3
[1, 2]
"""