Python 拷贝对象(深拷贝deepcopy与浅拷贝copy)
转自:http://www.jb51.net/article/15714.htm
Python中的对象之间赋值时是按引用传递的,如果需要拷贝对象,需要使用标准库中的copy模块。 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。 2. copy.deepcopy 深拷贝 拷贝对象及其子对象 一个很好的例子:
import copy
a = [
1,
2,
3,
4, [
'a',
'b']]
b = a
c = copy.copy(a)
d = copy.deepcopy(a)
a.append(
5)
a[
4].append(
'c')
print 'a = ', a
print 'b = ', b
print 'c = ', c
print 'd = ', d
输出结果: 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’]]
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