import pandas as pd df = pd.read_csv('new_events_data.csv') grouped_data = df.groupby('user_id')['product_id'].agg(list).reset_index() user_product_dict = dict(zip(grouped_data['user_id'], grouped_data['product_id'])) for key, value in user_product_dict.items(): print(key, value) break user_id_list = list(user_product_dict.keys()) print(len(user_id_list)) print(len(user_product_dict)) import pickle def save_obj(obj, name): with open(name, 'wb') as f: pickle.dump(obj, f) save_obj(user_product_dict, 'user_product_dict.pkl') save_obj(user_id_list, 'user_id_list.pkl')