Ensuring column uniqueness in a Pandas DataFrame

Last update on April 09 2025 12:55:08 (UTC/GMT +8 hours)

7. Checking That a Specific Column Contains Only Unique Values

Write a Pandas program to check that a specific column contains only unique values.

This exercise demonstrates how to ensure that a specific column contains only unique values by checking for duplicates.

Sample Solution :

Code :

import pandas as pd

# Create a sample DataFrame
df = pd.DataFrame({
    'ID': [1, 2, 3, 3],
    'Name': ['Orville', 'Arturo', 'Ruth', 'David']
})

# Check if the 'ID' column has unique values
unique_ids = df['ID'].is_unique

# Output the result
print(f"Is 'ID' column unique? {unique_ids}")

Output:

Is 'ID' column unique? False

Explanation:

• Created a DataFrame with an 'ID' column that contains duplicate values.
• Used is_unique to check if the 'ID' column contains only unique values.
• Displayed whether the 'ID' column is unique.

For more Practice: Solve these Related Problems:

• Write a Pandas program to verify that a specific column contains only unique values and flag any duplicates.
• Write a Pandas program to identify and list duplicate entries in a column that is expected to have unique values.
• Write a Pandas program to enforce uniqueness on a specific column and output the rows that break this rule.
• Write a Pandas program to compare the number of unique values in a column with the total row count and report discrepancies.

Python-Pandas Code Editor:

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