Compare two dataframes by index with unique indexes-CodePudding

I want to compare two dataframes by index using pd.Dataframe.eq() to get a dataframe with true/false values

But the two dataframes have unique indexes, so I mean that df1 contains a index that is not represented in df2 and vice versa.

I am interested if columns 'a' 'b' 'c' of df1 contain the same value (0 or 1 ) of df2, for each row

df1 = pd.DataFrame({'a':[1,1,1,1,1], 'b':[0,1,0,1,0], 'c':[1,0,0,1,1]}, index=['1_1', '1_2', '2_1', '2_2', '2_3'])
df2 = pd.DataFrame({'a':[0,1,1,1,1,0], 'b':[1,0,1,0,1,0], 'c':[1,1,1,1,1,0]}, index=['1_1', '1_2', '1_3', '2_2', '2_3', '2_4'])

df1.eq(df2)

yields

1_1,False,False,True
1_2,True,False,False
1_3,False,False,False
2_1,False,False,False
2_2,True,False,True
2_3,True,False,True
2_4,False,False,False

and it should look like

1_1,False,False,True
1_2,True,False,False
2_2,True,False,True
2_3,True,False,True

I am not quite sure how to approach the issue of unique indexes. I was thinking about merging the dfs but then I stubble at comparing the columns

Thanks for the help

CodePudding user response：

Seems you only want to keep comparison results for indices that exist in both dataframes, and in this case, you can get the common set of indices by

idx = df1.index.intersection(df2.index)

then

df1.loc[idx].eq(df2.loc[idx])

df1.eq(df2).loc[idx]