Merging DataFrames and Renaming Columns in Pandas

Last update on April 09 2025 12:52:05 (UTC/GMT +8 hours)

18. Merge and Rename Columns

Write a Pandas program to merge DataFrames and rename columns after merge.

This exercise shows how to merge DataFrames and rename specific columns in the resulting DataFrame.

Sample Solution :

Code :

import pandas as pd

# Create two sample DataFrames
df1 = pd.DataFrame({
    'ID': [1, 2, 3],
    'Name': ['Selena', 'Annabel', 'Caeso']
})

df2 = pd.DataFrame({
    'ID': [1, 2, 3],
    'Salary': [50000, 60000, 70000]
})

# Merge the DataFrames on the 'ID' column
merged_df = pd.merge(df1, df2, on='ID')

# Rename the 'Salary' column to 'Annual_Income'
merged_df.rename(columns={'Salary': 'Annual_Income'}, inplace=True)

# Output the result
print(merged_df)

Output:

   ID     Name  Annual_Income
0   1   Selena          50000
1   2  Annabel          60000
2   3    Caeso          70000

Explanation:

• Created two DataFrames df1 and df2.
• Merged them on the 'ID' column using pd.merge().
• Renamed the 'Salary' column to 'Annual_Income' using rename().

For more Practice: Solve these Related Problems:

• Write a Pandas program to merge two DataFrames and then rename columns based on a provided mapping dictionary.
• Write a Pandas program to merge two DataFrames and rename duplicate columns by appending a suffix that indicates their origin.
• Write a Pandas program to merge two DataFrames and then rename the key column to a standardized name across multiple DataFrames.
• Write a Pandas program to merge two DataFrames and then convert all column names to uppercase after merging.

Python-Pandas Code Editor:

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