python - 列表分配

Question

这个问题已经有答案了:

How do I clone a list so that it doesn't change unexpectedly after assignment? (24 个回答)

已关闭 6 年前。

我有这样的列表，

a=['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']
b=['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']
c=['name test', 'maximum-net-data-rate 4294967296', 'minimum-expected-throughput 1', 'maximum-gamma-data-rate 4294967296', 'minimum-gamma-data-rate 1']

这里我尝试将列表“a”中的每个元素一一替换为列表“c”中的元素。我尝试了这段代码:

for i in range(len(a)):
    a[i]=c[i]
    print a
    a=['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']

通过这段代码，我得到了正确的输出:

['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']
['name test', 'maximum-net-data-rate 4294967296', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']
['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 1', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 0']
['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967296', 'minimum-gamma-data-rate 0']
['name test', 'maximum-net-data-rate 4294967295', 'minimum-expected-throughput 0', 'maximum-gamma-data-rate 4294967295', 'minimum-gamma-data-rate 1']

但是当我将最后一条语句(分配)替换为

for i in range(len(a)):
    a[i]=c[i]
    print a
    a=b

列表“b”也在更新。我怎样才能在不直接分配整个列表的情况下实现这一目标。

Answer 1

只需将最后一行替换为:

a=b[:]