class A():
  def go(self):
    print ("go A go!")
  def stop(self):
    print ("stop A stop!")
  def pause(self):
    raise Exception("Not Implemented")
class B(A):
  def go(self):
    super(B, self).go()
    print ("go B go!")
class C(A):
  def go(self):
    super(C, self).go()
    print ("go C go!")
  def stop(self):
    super(C, self).stop()
    print ("stop C stop!")
class D(B,C):
  def go(self):
    super(D, self).go()
    print ("go D go!")
  def stop(self):
    super(D, self).stop()
    print ("stop D stop!")
  def pause(self):
    print ("wait D wait!")
class E(B,C):
  pass
a = A()
b = B()
c = C()
d = D()
e = E()
# 说明下列代码的输出结果
a.go()
print('--------')
b.go()
print('--------')
c.go()
print('--------')
d.go()
print('--------')
e.go()
print('--------')
a.stop()
print('--------')
b.stop()
print('--------')
c.stop()
print('--------')
d.stop()
print('--------')
e.stop()
print(D.mro())
a.pause()
b.pause()
c.pause()
d.pause()
e.pause()

a.go()# go A go!
b.go()# go A go!# go B go!
c.go()# go A go!# go C go!
d.go()# go A go!# go C go!# go B go!# go D go!
e.go()# go A go!# go C go!# go B go!
a.stop()# stop A stop!
b.stop()# stop A stop!
c.stop()# stop A stop!# stop C stop!
d.stop()# stop A stop!# stop C stop!# stop D stop!
e.stop()# stop A stop!
a.pause()# ... Exception: Not Implemented
b.pause()# ... Exception: Not Implemented
c.pause()# ... Exception: Not Implemented
d.pause()# wait D wait!
e.pause()# ...Exception: Not Implemented

class A:
  def __init__(self):
    self.n = 2
  def add(self, m):
    print('self is {0} @A.add'.format(self))
    self.n += m
class B(A):
  def __init__(self):
    self.n = 3
  def add(self, m):
    print('self is {0} @B.add'.format(self))
    super().add(m)
    print('newb')
    self.n += 3
class C(A):
  def __init__(self):
    self.n = 4
  def add(self, m):
    print('self is {0} @C.add'.format(self))
    super().add(m)
    print('newc')
    self.n += 4
class D(B, C):
  def __init__(self):
    self.n = 5
  def add(self, m):
    print('self is {0} @D.add'.format(self))
    super().add(m)
    self.n += 5
d = D()
d.add(2)
print(d.n)