请大家看看这段代码,为什么不能够正常输出呢?
class apple(object):
def __init__(self, a):
self.a = a
print 'apple ...'
class bpple(apple):
def __init__(self, a, b):
super(bpple, self).__init__(a)
self.b = b
print 'bpple ...'
class cpple(apple):
def __init__(self, a, c):
super(cpple, self).__init__(a)
self.c = c
print 'cpple ...'
class dpple(bpple, cpple):
def __init__(self,a, b, c, d):
super(dpple, self).__init__(a,b,c)
self.d = d
print 'dpple ...'
d = dpple('a', 'b', 'c', 'd')