python 深拷贝和浅拷贝浅析

Posted 2020-08-12

简单点说

1. copy.copy 浅拷贝 只拷贝父对象，不会拷贝对象的内部的子对象。id会变化
2. copy.deepcopy 深拷贝 拷贝对象及其子对象。id会变化

 

>>> import copy
>>> a=[1,2,3,[4,5,6]]
>>> b=a                              #普通赋值
>>> c=copy.copy(a)            #浅拷贝
>>> d=copy.deepcopy(a)    #深拷贝
>>> print(a,b,c,d)
[1, 2, 3, [4, 5, 6]] [1, 2, 3, [4, 5, 6]] [1, 2, 3, [4, 5, 6]] [1, 2, 3, [4, 5,
6]]
#------------------------------------------------------------------------------
>>> a[3].append("chen")
>>> print(a)
[1, 2, 3, [4, 5, 6, ‘chen‘]]
>>> print(b)
[1, 2, 3, [4, 5, 6, ‘chen‘]]
>>> print(c)
[1, 2, 3, [4, 5, 6, ‘chen‘]]
>>> print(d)
[1, 2, 3, [4, 5, 6]]
#------------------------------------------------------------------------------
>>> a.append("wang")
>>> print(a)
[1, 2, 3, [4, 5, 6, ‘chen‘], ‘wang‘]
>>> print(b)
[1, 2, 3, [4, 5, 6, ‘chen‘], ‘wang‘]
>>> print(c)
[1, 2, 3, [4, 5, 6, ‘chen‘]]
>>> print(d)
[1, 2, 3, [4, 5, 6]]                            

 

 

 

 

 

 

 

 

 

 

 

 

 

 

dd