มีกิจกรรมการประชุมประจำปีเกิดขึ้นในภูมิภาคสหราชอาณาจักรกี่ครั้ง
How many Annual Meeting events happened in the United Kingdom region?
df1 = pd.DataFrame(columns=['party_id', 'event_name']); df2 = pd.DataFrame(columns=['region_id', 'region_name']); df3 = pd.DataFrame(columns=['region_id', 'party_id'])
df1.loc[(df1['event_name'] == 'Annual Meeting') & df1['party_id'].isin(df3['party_id'].loc[df3['region_id'].isin(df2.loc[df2['region_name'] == 'United Kingdom']['region_id'])])].shape[0]