text_plain_output_1.png
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)

books = pd.read_csv('../input/Books.csv', encoding='ISO 8859-1')
users = pd.read_csv('../input/Users.csv', encoding='ISO 8859-1')
book_ratings = pd.read_csv('../input/BookRatings.csv', encoding='ISO 8859-1', low_memory=False)

book_ratings['UserID'] = book_ratings.UserID.astype(int)
grouped_cleaned = book_ratings.groupby(['UserID', 'ISBN']).sum().reset_index()
grouped_cleaned = grouped_cleaned.query('BookRating > 0')

grouped_cleaned.shape