แสดงรายชื่อศิลปินทั้งหมดที่ไม่มีนิทรรศการในปี 2547
Show all artist names who didn't have an exhibition in 2004.
df_exhibition = pd.DataFrame(columns=['artist_id', 'year']); df_artist = pd.DataFrame(columns=['name', 'artist_id'])
df_artist[~df_artist['artist_id'].isin(df_exhibition[df_exhibition['year'] == '2004']['artist_id'])]['name']