ความสูงเฉลี่ยของผู้เล่นจากวิทยาลัยชื่อ 'Yale University' คือเท่าใด
What is the average height of the players from the college named 'Yale University'?
df_player_college = pd.DataFrame(columns=['player_id', 'college_id']); df_player = pd.DataFrame(columns=['height', 'player_id']); df_college = pd.DataFrame(columns=['college_id', 'name_full'])
df_player.merge(df_player_college, on='player_id').merge(df_college[df_college['name_full'] == 'Yale University'], on='college_id')['height'].mean()