How can I Change Column Names in a Pandas DataFrame?

You can change the column names in a pandas DataFrame in several ways:

1. Using rename() Method (for Renaming Specific Columns)

import pandas as pd

# Example DataFrame
df = pd.DataFrame({
    'A': [1, 2, 3],
    'B': [4, 5, 6],
    'C': [7, 8, 9]
})

# Renaming specific columns
df.rename(columns={'A': 'Alpha', 'B': 'Beta'}, inplace=True)
print(df)

Output:

   Alpha  Beta  C
0      1     4  7
1      2     5  8
2      3     6  9

• Use inplace=True to apply changes directly to the original DataFrame, or omit it to return a new DataFrame.

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2. Assigning a New List to df.columns (for Renaming All Columns)

# Renaming all columns at once
df.columns = ['X', 'Y', 'Z']
print(df)

Output:

   X  Y  Z
0  1  4  7
1  2  5  8
2  3  6  9

• Ensure the list length matches the number of existing columns.

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3. Using List Comprehension (for Dynamic Renaming)

# Adding a prefix to all column names
df.columns = [col + '_new' for col in df.columns]
print(df)

Output:

   X_new  Y_new  Z_new
0      1      4      7
1      2      5      8
2      3      6      9

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4. Using set_axis() Method

# Renaming all columns
df = df.set_axis(['One', 'Two', 'Three'], axis=1, inplace=False)
print(df)

Output:

   One  Two  Three
0    1    4      7
1    2    5      8
2    3    6      9

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✅ Summary

• For specific columns: Use rename().
• For all columns: Assign a new list to df.columns or use set_axis().
• For dynamic changes: Use list comprehension.