Python裏的拷貝

引用和copy(),deepcopy()的區別

import copy
a = [1, 2, 3, 4, [‘a‘, ‘b‘]]  #原始對象

b = a  #賦值，傳對象的引用
c = copy.copy(a)  #對象拷貝，淺拷貝
d = copy.deepcopy(a)  #對象拷貝，深拷貝

a.append(5)  #修改對象a
a[4].append(‘c‘)  #修改對象a中的[‘a‘, ‘b‘]數組對象

print ‘a = ‘, a
print ‘b = ‘, b
print ‘c = ‘, c
print ‘d = ‘, d

輸出結果：
a =  [1, 2, 3, 4, [‘a‘, ‘b‘, ‘c‘], 5]
b =  [1, 2, 3, 4, [‘a‘, ‘b‘, ‘c‘], 5]
c =  [1, 2, 3, 4, [‘a‘, ‘b‘, ‘c‘]]
d =  [1, 2, 3, 4, [‘a‘, ‘b‘]]
 

Python裏的拷貝