อัศวินดำปรากฏตัวครั้งแรกในรอบชิงไม่ถึง 1 ครั้งในปีใด?
What is the year of the first appearance of the Black Knights, who had less than 1 finals appearances?
df = pd.DataFrame(columns=['year_of_first_appearance', 'corps_name', 'number_of_finals_appearances'])
df.loc[(df['corps_name'] == 'black knights') & (df['number_of_finals_appearances'] < '1'), 'year_of_first_appearance'].count()