ค้นหานามสกุลของนักเรียนชั้นประถมศึกษาปีที่ 3 ที่ไม่ได้สอนโดย COVIN JEROME
Find the last names of the students in third grade that are not taught by COVIN JEROME.
df_list = pd.DataFrame(columns=['lastname', 'classroom', 'grade']); df_teachers = pd.DataFrame(columns=['classroom', 'lastname', 'firstname'])
df_list[(df_list['grade'] == 3) & (~df_list['classroom'].isin(df_teachers[(df_teachers['firstname'] != 'COVIN') | (df_teachers['lastname'] != 'JEROME')]['classroom']))]['lastname'].unique()