Delete Duplicate Emails — LeetCode 196 Python Solution

The problem

Delete the duplicate rows so that only the row with the smallest id survives for each email address, leaving every other row untouched. The Person table has id (int, primary key) and email (varchar), and the addresses never contain uppercase letters. The answer changes the table in place rather than returning a result set.

Example

Input

Person(id, email) = (1, 'ana@example.com'), (2, 'ben@example.com'), (3, 'ana@example.com'), (4, 'ana@example.com')

Output

Person(id, email) = (1, 'ana@example.com'), (2, 'ben@example.com')

Explanation

Ids 3 and 4 duplicate an address already held by id 1, so only the smallest id per address survives.

Python solution

import pandas as pd


# Modify Person in place
def delete_duplicate_emails(person: pd.DataFrame) -> None:
    # Sort the rows based on id (Ascending order)
    person.sort_values(by="id", ascending=True, inplace=True)
    # Drop the duplicates based on email.
    person.drop_duplicates(subset="email", keep="first", inplace=True)

Complexity

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