Setting values with .loc in Pandas DataFrame

Last update on September 06 2025 12:48:31 (UTC/GMT +8 hours)

11. Setting Values Using .loc

Write a Pandas program that uses .loc to set values in the DataFrame.

Sample Solution :

Python Code :

import pandas as pd

# Create a DataFrame
df = pd.DataFrame({
    'X': [1, 6, 8, 3, 7],
    'Y': [5, 2, 9, 4, 1]
})

# Set values using .loc
df.loc[df['X'] > 5, 'Y'] = 0
print(df)

Output:

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

Explanation:

• Import pandas library.
• Create a DataFrame.
• Use .loc to set values in column 'Y' where column 'X' > 5.
• Print the DataFrame.

For more Practice: Solve these Related Problems:

• Write a Pandas program to use .loc to update specific values in a DataFrame and then display the modified DataFrame.
• Write a Pandas program to set new values in a DataFrame column for rows that meet a condition using .loc.
• Write a Pandas program to modify a DataFrame by assigning a constant value to a subset of rows using .loc and verify the change.
• Write a Pandas program to use .loc to set values in multiple columns simultaneously for rows meeting a given condition.

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