102. Classes More Than 5 Students

[문제]

https://leetcode.com/problems/classes-more-than-5-students/

 

[풀이]

1. class로 그룹화 해준 뒤 student의 수를 세어준다

2. student 수가 5이상 행들만 필터링하고 class열만 출력한다

 

Pandas

import pandas as pd

def find_classes(courses: pd.DataFrame) -> pd.DataFrame:
    df = courses.groupby('class')['student'].count().reset_index(name='cnt')
    return df[df['cnt'] >= 5][['class']]

 

SQL

SELECT class
FROM Courses
GROUP BY class
HAVING COUNT(student) >= 5