Duplicate Emails — LeetCode 182 Python Solution

The problem

Report every email address that is recorded more than once. The Person table has id (int, primary key) and email (varchar), one row per record, and the addresses never contain uppercase letters. Each duplicated address should be listed once, in a column named Email.

Example

Input

Person(id, email) = (1, 'ana@example.com'), (2, 'cleo@example.com'), (3, 'ana@example.com'), (4, 'ben@example.com'), (5, 'ben@example.com')

Output

Email = 'ana@example.com', 'ben@example.com'

Explanation

Both addresses occur twice, so each is reported once; cleo@example.com occurs once and is excluded.

Python solution

import pandas as pd


def duplicate_emails(person: pd.DataFrame) -> pd.DataFrame:
    results = pd.DataFrame()

    results = person.loc[person.duplicated(subset=["email"]), ["email"]]

    return results.drop_duplicates()

Complexity

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