df1
col1 col2
1 A
1 A
2
3
4 D
4 D
df2
coln1 coln2
1 A
2 B
3 c
4 D
df1(col2) = df1(col2).map(df2.set_index(coln1)[coln2])
Trying to fill col2 value in df1 from df2 where df1.col1 = df2.coln1
here both datasets are large, imported from csv files, Please help me to correct above code.
If below error comes, how to handle this also
InvalidIndexError: Reindexing only valid with uniquely valued Index objects
