Elegant & Short | Pandas vs SQL | Simple RegEx
```PostgreSQL []
SELECT user_id,
       email
  FROM users
 WHERE email ~ '^\w+@\w+\.com$'
 ORDER BY user_id;
```
```MySQL []
SELECT user_id,
       email
  FROM users
 WHERE regexp_like(email, '[a-zA-Z0-9_]+@[a-zA-Z0-9_]+\.com$')
 ORDER BY user_id;
```
```Oracle []
SELECT user_id,
       email
  FROM users
 WHERE regexp_like(email, '^[[:alnum:]_]+@[[:alnum:]]+\.com$')
 ORDER BY user_id;
```
```Python []
def find_valid_emails(users: pd.DataFrame) -> pd.DataFrame:
    valid_emails = users[users['email'].str.match(r'^\w+@\w+\.com$', na=False)]
    valid_emails = valid_emails.sort_values(by='user_id')
    return valid_emails
```
['Python3', 'MySQL', 'Oracle', 'PostgreSQL', 'Pandas']