Python数组列插入

我在python中使用数组，我想在2d数组中插入一个数组作为列 我发现，出于某种原因，我的专栏只写了单词的最后一个元素[]

words = ['first','second','third','fourth','fifth']
tab = [[None]*5]*len(words)
for i in range(len(words)):
    tab[i][0] = words[i]
for i in range(len(words)):
    print(tab[i])


#output
['fifth', None, None, None, None]
['fifth', None, None, None, None]
['fifth', None, None, None, None]
['fifth', None, None, None, None]
['fifth', None, None, None, None]

---

您正在使用复制值

[None]*5

及

你的需要：

words = ['first','second','third','fourth','fifth']
tab = [[[None] for i in range(5)] for i in range(len(words))]
for i in range(len(words)):
    tab[i][0] = words[i]
for i in range(len(words)):
    print(tab[I])

出局

---

你的预期输出是什么？谢谢，但我不明白我们是怎么得到这个的：它有点像字符串池？[[None]因为我在范围（5）]中意味着五步[None]：[[None]，[None]，[None]，[None]，[None]，[None]，[None]，[None]，[None]，[None]]当你使用“[[None]*5]*len（words）”，主要问题是：“*len（words）”你只复制它，而改变之痒就是你的改变所有这一切所以参考文献也是“克隆的”是的你是对的！它的克隆）

words = ['first','second','third','fourth','fifth']
tab = [[[None] for i in range(5)] for i in range(len(words))]
for i in range(len(words)):
    tab[i][0] = words[i]
for i in range(len(words)):
    print(tab[I])

['first', [None], [None], [None], [None]]
['second', [None], [None], [None], [None]]
['third', [None], [None], [None], [None]]
['fourth', [None], [None], [None], [None]]
['fifth', [None], [None], [None], [None]]
>>>