วิทยาลัยไหนมีทั้งผู้เล่นตำแหน่งกองกลางและผู้เล่นตำแหน่งกองหลัง?
Which college have both players with position midfielder and players with position defender?
match_season = pd.DataFrame(columns=['College', 'POSITION'])
set(match_season[match_season['POSITION']=='Midfielder']['College']).intersection(set(match_season[match_season['POSITION']=='Defender']['College']))