Python 将二维数组转换为两列数据框熊猫
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turning a two dimensional array into a two column dataframe pandas
提问by user3314418
if I have the following, how do I make pd.DataFrame() turn this array into a dataframe with two columns. What's the most efficient way? My current approach involves creating copies out of each into a series and making dataframes out of them.
如果我有以下内容，我如何使 pd.DataFrame() 将此数组转换为具有两列的数据框。最有效的方法是什么？我目前的方法涉及将每个副本创建为一个系列并从中制作数据帧。
From this:
由此：
([[u'294 (24%) L', u'294 (26%) R'],
[u'981 (71%) L', u'981 (82%) R'],])
to
到
x y
294 294
981 981
rather than
而不是
x
[u'294 (24%) L', u'294 (26%) R']
my current approach. Looking for something more efficient
我目前的做法。寻找更有效的东西
numL = pd.Series(numlist).map(lambda x: x[0])
numR = pd.Series(numlist).map(lambda x: x[1])
nL = pd.DataFrame(numL, columns=['left_num'])
nR = pd.DataFrame(numR, columns=['right_num'])
nLR = nL.join(nR)
nLR
UPDATE**
更新**
I noticed that my error simply comes down to when you pd.DataFrame() a list versus a series. WHen you create a dataframe out of a list, it merges the items into the same column. Not so with a list. That solved my problem in the most efficient way.
我注意到我的错误只是归结为 pd.DataFrame() 是列表还是系列。当您从列表中创建数据框时，它会将项目合并到同一列中。列表不是这样。这以最有效的方式解决了我的问题。
采纳答案by unutbu
In [172]: data = [[u'294 (24%) L', u'294 (26%) R'], [u'981 (71%) L', u'981 (82%) R'],]
In [173]: clean_data = [[int(item.split()[0]) for item in row] for row in data]
In [174]: clean_data
Out[174]: [[294, 294], [981, 981]]
In [175]: pd.DataFrame(clean_data, columns=list('xy'))
Out[175]:
x y
0 294 294
1 981 981
[2 rows x 2 columns]
