在 Python 中循环遍历列表 [英] Looping over a list in Python

问题描述

我有一个包含子列表的列表.我想打印长度等于 3 的所有子列表.

我在 python 中执行以下操作:

 for x in values[:]:如果 len(x) == 3:打印(x)

values 是原始列表.上面的代码是否为 x 的每个值打印每个长度等于 3 的子列表?我想只显示 length == 3 一次的子列表.

问题解决了.问题出在 Eclipse 编辑器上.我不明白原因，但是当我运行循环时它只显示我列表的一半.

我需要在 Eclipse 中更改任何设置吗?

解决方案

x in mylist 比 x in mylist[:] 和你的 更好，更易读>len(x) 应该等于 3.

<预><代码>>>>mylist = [[1,2,3],[4,5,6,7],[8,9,10]]>>>对于 mylist 中的 x:...如果 len(x)==3:... 打印 x...[1, 2, 3][8, 9, 10]

或者如果您需要更多 Pythonic 使用 list-comprehensions

<预><代码>>>>[x for x in mylist if len(x)==3][[1, 2, 3], [8, 9, 10]]>>>

I have a list with sublists in it. I want to print all the sublists with length equal to 3.

I am doing the following in python:

for x in values[:]:
    if len(x) == 3:
        print(x)

values is the original list. Does the above code print every sublist with length equal to 3 for each value of x? I want to display the sublists where length == 3 only once.

The problem is solved. The problem is with the Eclipse editor. I don't understand the reason, but it is displaying only half of my list when I run my loop.

Are there any settings I have to change in Eclipse?

解决方案

x in mylist is better and more readable than x in mylist[:] and your len(x) should be equal to 3.

>>> mylist = [[1,2,3],[4,5,6,7],[8,9,10]]
>>> for x in mylist:
...      if len(x)==3:
...        print x
...
[1, 2, 3]
[8, 9, 10]

or if you need more pythonic use list-comprehensions

>>> [x for x in mylist if len(x)==3]
[[1, 2, 3], [8, 9, 10]]
>>>

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