python 覆写（override）

class A(object):


    def __init__(self):
        print 'Enter A'
        print 'Leave A'
        pass


    def myprint(self):
        print 'Enter print of A'
        print 'Leave print of A'


    def myecho(self):
        print 'In echo of A'


class B(A):


    def __init__(self):
        print "Enter B"
        super(B, self).__init__()
        print "Leave B"


    def myprint(self):
        print 'Enter print of B'
        super(B, self).myprint()
        print 'Leave print of B'


class C(A):


    def __init__(self):
        print 'Enter C'
        print 'Leave C'


    def myprint(self):
        print 'In print of C'


print '-------------------------------'
b = B()
print '-------------------------------'
b.myprint()
print '-------------------------------'
c = C()
c.myprint()
c.myecho()
print '-------------------------------'
a = A()
a.myprint()
a.myecho()

输出结果：
-------------------------------
Enter B
Enter A
Leave A
Leave B
-------------------------------
Enter print of B
Enter print of A
Leave print of A
Leave print of B
-------------------------------
Enter C
Leave C
In print of C
In echo of A
-------------------------------
Enter A
Leave A
Enter print of A
Leave print of A
In echo of A