class A():
    _a = 1

    def Afun(self):
        print 'A'

    def Common(self):
        print 'A-common'        

class A1():    
    def Common(self):
        print 'A1-common'   
        
class B(A,A1):
    _b = 2
    def Bfun(self):
        print 'B'

b = B()

b.Common()

可在http://codepad.org中进行在线调试；或http://ideone.com ； http://kodingen.com/