使用pandas.to_csv（df）仅在Excel中显示numpy.array的子​​集

Question

我有一个pandas.DataFrame，有2列。第一列是一个简单的整数，第二列是长度为50的numpy.array。我想将这两列写入CSV文件，但是当我使用.to_csv()并在Excel中打开文件时只显示值的子集并且可以访问。长度是可变的，当我在Excel中打开它时，我似乎得到一个相同字符串长度（或多或少）的列。 pandas.to_csv（）是否对文件写了某种可视解释，而不是DataFrame中的实际数据？

如何正确地将其写入CSV以便我可以在Excel中使用它？

Answer 1

似乎第二列的50值位于Excel的每个行的一个单元格中。

我认为您可以使用apply numpy array和concat第一列Series创建a列新列。上次写to_csv：

import pandas as pd
import numpy as np

df = pd.DataFrame({'a': [0,1,5], 'b': [np.arange(50), np.arange(50), np.arange(50)]} )
print df
   a                                                  b
0  0  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,...
1  1  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,...
2  5  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,...    

print df.b.apply(pd.Series)
   0   1   2   3   4   5   6   7   8   9  ...  40  41  42  43  44  45  46  47  \
0   0   1   2   3   4   5   6   7   8   9 ...  40  41  42  43  44  45  46  47   
1   0   1   2   3   4   5   6   7   8   9 ...  40  41  42  43  44  45  46  47   
2   0   1   2   3   4   5   6   7   8   9 ...  40  41  42  43  44  45  46  47   

   48  49  
0  48  49  
1  48  49  
2  48  49  

df = pd.concat([df['a'], df.b.apply(pd.Series)], axis=1)
print df
[3 rows x 50 columns]
   a  0  1  2  3  4  5  6  7  8 ...  40  41  42  43  44  45  46  47  48  49
0  0  0  1  2  3  4  5  6  7  8 ...  40  41  42  43  44  45  46  47  48  49
1  1  0  1  2  3  4  5  6  7  8 ...  40  41  42  43  44  45  46  47  48  49
2  5  0  1  2  3  4  5  6  7  8 ...  40  41  42  43  44  45  46  47  48  49

#for testing
print df.to_csv()
#write to file
#print df.to_csv('filename')

,a,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49
0,0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49
1,1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49
2,5,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49

编辑：

如果您需要写DataFrame to_excel：

#write to excel, omit index of DataFrame
df.to_excel('test.xlsx', index=False)