Question

我有pandas DataFrame＆＃39; test_df＆＃39;：

email                      my_list
email1@email1.com          [1,9,3,5]
email2@email2.com          [6,3,3,15]
email3@email3.com          [7,7,2,5]
email4@email4.com          [5,5,5,5]

我如何拥有以下DataFrame（获取＆＃39; my_list＆＃39;的前2个元素）：

email                      col1             col2             
email1@email1.com          1                9        
email2@email2.com          6                3
email3@email3.com          7                7
email4@email4.com          5                5

我试过了：

test_df['col1'] = test_df['my_list'][0]
test_df['col2'] = test_df['my_list'][1]

但它不能正常工作

Answer 1

我问了一个相关的问题here，虽然我想要将列表扩展到列之外，所以答案比你需要的更复杂。在您的情况下，您可以这样做：

# Using my own example data since it's a bit tough to copy-paste
# a printed table and have the lists show up as lists
df = pd.DataFrame({'email': ['email1@eg.com', 'email2@eg.com'], 
                   'lists': [[1, 9, 3, 5], [6, 3, 3, 15]]})
df
Out[14]: 
           email          lists
0  email1@eg.com   [1, 9, 3, 5]
1  email2@eg.com  [6, 3, 3, 15]

objs = [df, pd.DataFrame(df['lists'].tolist()).iloc[:, :2]]
pd.concat(objs, axis=1).drop('lists', axis=1)
Out[13]: 
           email  0  1
0  email1@eg.com  1  9
1  email2@eg.com  6  3

Pandas DataFrame：从列内的列表创建列

1 个答案: