经典类

经典类和新式类:

# !/usr/bin/env python
# -*- coding: utf-8 -*-
class P1: #(object): # parent class 1 父类 1
 def foo(self):
   print 'called P1-foo()'

class P2: #(object): # parent class 2 父类 2
  def foo(self):
      print 'called P2-foo()'
  def bar(self):
      print 'called P2-bar()'
class C1(P1, P2): # child 1 der. from P1, P2 #子类 1，从 P1，P2 派生
   pass

class C2(P1, P2): # child 2 der. from P1, P2 #子类 2，从 P1，P2 派生
  def bar(self):
     print 'called C2-bar()'

class GC(C1, C2): # define grandchild class #定义子孙类
   pass  # derived from C1 and C2 #从 C1，C2 派生

gc = GC()
print gc.bar()
当调用foo()时,它首先在当前类(GC)中查找,如果没找到,就向上查找最亲的父类,C1.

查找未遂,就继续沿树上访到类P1，foo()被找到。


对 bar()来说，它通过搜索 GC，C1，P1 然后在 P2 中找到。因为使用这种解释顺序的缘故，
C2.bar()根本就不会被搜索了。


新式类:
# !/usr/bin/env python
# -*- coding: utf-8 -*-
class P1(object): # parent class 1 父类 1
 def foo(self):
   print 'called P1-foo()'

class P2(object): # parent class 2 父类 2
  def foo(self):
      print 'called P2-foo()'
  def bar(self):
      print 'called P2-bar()'
class C1(P1, P2): # child 1 der. from P1, P2 #子类 1，从 P1，P2 派生
   pass

class C2(P1, P2): # child 2 der. from P1, P2 #子类 2，从 P1，P2 派生
  def bar(self):
     print 'called C2-bar()'

class GC(C1, C2): # define grandchild class #定义子孙类
   pass  # derived from C1 and C2 #从 C1，C2 派生

gc = GC()
print gc.bar()

C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/eeeee/a10.py
called P2-bar()
None