Replace values of a column in DF1 with corresponding values in DF2

Question

I got two dataframes:

DF1: Index(['Name', 'Timestamp'], dtype='object') // 34424 rows × 2 columns

DF2: Index(['Name', 'Description'], dtype='object') // 103 rows × 2 columns

I want to replace the values in DF1["Name"] with the corresponding Description in DF2["Description"]

I tried the following code:

DF1['Name'] = DF2['Name'].map(DF1_index('Name')['Description'])
DF1

Error: "Description"

score 0 · Accepted Answer · answered Aug 10 '20 at 12:00

0

You can use merge for that:

df_merged = DF1.merge(DF2, on=["Name"], how="left")

If you want to keep the original index (DF2 has to have unique "Name" values though):

df_merged = DF1.reset_index().merge(DF2, on=["Name"], how="left").set_index("index")

answered Aug 10 '20 at 12:00

Andreas

Do you think merge function will work with dataframes with different sizes? – Marco Diebold Aug 10 '20 at 12:10
have you tested it? yes it definetly does. – Andreas Aug 10 '20 at 12:16

1 Answers1