python浅复制 和 深复制

直接赋值：对象引用。
浅拷贝：拷贝父对象，不拷子对象
深拷贝： 使用copy 模块 deepcopy 方法，拷贝父、子对象
实例：

import copy
a1 = [11, 22, 33, 44,55, ['China', 'Russia','America']] 
a2 = a1                      
a3 = copy.copy(a1)           
a4 = copy.deepcopy(a1)       

a1.append('haha')                 
a1[5].remove('America')    
 
print( 'a1 = ', a1 )
print( 'a2= ', a2 )
print( 'a3 = ', a3 )
print( 'a4 = ', a4 )
```python
#以上实例输出结果
a1=[11, 22, 33, 44, 55, ['China', 'Russia'], 'haha']
a2=[11, 22, 33, 44, 55, ['China', 'Russia'], 'haha']
a3=[11, 22, 33, 44, 55, ['China', 'Russia'], 'haha']
a4=[11, 22, 33, 44,55, ['China', 'Russia','America']] 

参考：《Python 直接赋值、浅拷贝和深度拷贝解析》