Python - 如何获取每个列表的第一行？

I need to get each row of a list and make a new list. Let me explain.

我需要获取列表的每一行并创建一个新列表。让我解释。

I have this:

我有这个：

data = [[204.0, u'stock'], [204.0, u'stock']]

I need to transform in this:

我需要改变这个：

column1 = [204.0, 204.0]
colunm2 = [u'stock', u'stock']

Any clues on how can this be done?

关于如何做到这一点的任何线索？

Best Regards,

最好的祝福，

3 个解决方案

#1

Use zip():

使用zip（）：

>>> data = [[204.0, u'stock'], [204.0, u'stock']]
>>> zip(*data)
[(204.0, 204.0), (u'stock', u'stock')]
>>> column1, column2 = zip(*data)
>>> column1
(204.0, 204.0)
>>> column2
(u'stock', u'stock')

Or, izip() from itertools:

或者，来自itertools的izip（）：

>>> from itertools import izip
>>> column1, column2 = izip(*data)
>>> column1
(204.0, 204.0)
>>> column2
(u'stock', u'stock')

#2

A simple list comprehension will do the trick.

一个简单的列表理解就可以了。

data = [[204.0, u'stock'], [204.0, u'stock']]

column1 = [i[0] for i in data]
column2 = [i[1] for i in data]

>>> column1
 [204.0, 204.0]
>>> column2
 ['stock', 'stock']

#3

may be , in one line

可能是，在一行

>>> data = [[204.0, u'stock'], [204.0, u'stock']]
>>> columns = [ [d[k] for d in data] for k in range(2)]
[[204.0, 204.0], ['stock', 'stock']]
>>> columns[0]
[204.0, 204.0]

and if the size of variable can change you can do this :

如果变量的大小可以改变，你可以这样做：

columns = [ [d[k] for d in data] for k in range(max(map(len,data)))]

#1