Implement Python magic decorator

property-v1.py

class PropertyDescriptor():
    def __init__(self, getmethod):
        self.getmethod = getmethod

    def __get__(self, obj, cls=None):
        return self.getmethod(obj)

def my_property(f):
    return PropertyDescriptor(f)

class A(object):
    @my_property
    def c(self):
        print('visit c')
        return 1

    b = 3

a = A()
print(a.c)