ผลงานของศิลปินคนไหนคือผีเสื้อเสือหางแฉก?
Which artist's work is the butterfly Tiger Swallowtail?
df = pd.DataFrame({'artist': ['John', 'Jane'], 'butterfly': ['moth', 'tiger swallowtail']})
df.loc[df['butterfly'] == 'tiger swallowtail', 'artist']