มีผลงานตีพิมพ์เรื่อง "อัตสึชิ โอโฮริ" กี่เรื่อง?
How many papers have "Atsushi Ohori" published?
authorship = pd.DataFrame(columns=['authid', 'paperid']); authors = pd.DataFrame(columns=['authid', 'fname', 'lname']); papers = pd.DataFrame(columns=['paperid'])
papers.loc[papers['paperid'].isin(authorship.loc[authors[(authors['fname'] == 'Atsushi') & (authors['lname'] == 'Ohori')]['authid'], 'paperid']), 'paperid'].nunique()