How to transform column values of a dataframe to another dataframe with different indexes?

Question

I have two dataframes with equal number of rows.

df_a:

index   Id   X   Y
1       10   x1  - 
2       20   x2  -

-----------

df_b:

index   PostId   Text   
3       10       abcd
4       20       efg

Now how can I transform values of df_b['Text'] to df_a['Y'] . resulting this:

df_a:

index   Id   X   Y
1       10   x1  abcd
2       20   x2  efg

Note that indexes of mentioned dataframes are not the same.

Answer 1

Because of the same number of rows, you can assign numpy array:

df_a['Y'] = df_b['Text'].to_numpy()

Older pandas versions:

df_a['Y'] = df_b['Text'].values

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If want to map or merge be free to use some of solution from this answer .