python – 标记新列中数据帧之间的相似性

我想比较两个不同长度的pandas DataFrame并识别匹配的索引号.当值匹配时,我想在新列中标记这些值.

df1:
Index    Column 1
41660    Apple
41935    Banana
42100    StrawBerry
42599    Pineapple

df2:
Index    Column 1
42599    Pineapple

Output:
Index    Column 1    'Matching Index?'
41660    Apple
41935    Banana
42100    StrawBerry
42599    Pineapple   True

解决方法:

如果这些确实是索引,那么你可以在索引上使用交集：

In [61]:
df1.loc[df1.index.intersection(df2.index), 'flag'] = True
df1

Out[61]:
         Column 1  flag
Index                  
41660       Apple   NaN
41935      Banana   NaN
42100  StrawBerry   NaN
42599   Pineapple  True

否则使用isin：

In [63]:
df1.loc[df1['Index'].isin(df2['Index']), 'flag'] = True
df1

Out[63]:
   Index    Column 1  flag
0  41660       Apple   NaN
1  41935      Banana   NaN
2  42100  StrawBerry   NaN
3  42599   Pineapple  True