追加到列表-无结果 [英] Appending to list - None result

问题描述

数据:

lis_t = [['q', 'w', 'e'],['r', 't', 'y']]

预期结果:

lis_t = [['q', 'w', 'e', 'u'],['r', 't', 'y']]

问题描述:我试图添加到上面的列表中，但是无法添加相同的内容，因为它以某种方式导致没有结果.请帮助我了解我在做什么错.

problem description: I am trying to append to the list above however not able to append the same as it somehow results in none. Please help me understand what am I doing wrong.

编写代码:

lis_t = [['q', 'w', 'e'],['r', 't', 'y']]
lis_t[0] = lis_t[0].append('u')
print(lis_t[0])
print(lis_t)

输出:

None
[None, ['r', 't', 'y']]

推荐答案

lis_t [0] .append('u')会返回 None 值，然后您分配这是 lis_t [0] 的原因，这就是为什么您获得 None 值

lis_t[0].append('u') this returns None value and then you assigning this to lis_t[0] that's why you are getting None value

lis_t = [['q', 'w', 'e'],['r', 't', 'y']]
lis_t[0].append('u')
print(lis_t)

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