รายชื่อละครเพลงที่ไม่มีนักแสดง
List the name of musicals that do not have actors.
df_actor = pd.DataFrame(columns = ['Name', 'Musical_ID']); df_musical = pd.DataFrame(columns = ['Name', 'Musical_ID'])
df_musical[~df_musical['Musical_ID'].isin(df_actor['Musical_ID'])]['Name']