Little typo about make_datasets.py

[yijunshengjax]

# ReMap usr ids
user_unique = data['user'].unique().tolist()
user_map = dict(zip(user_unique, range(1, len(user_unique) + 1)))
user_map[-1] = 0
all_user_count = len(**_user_map_**)
data['user'] = data['user'].apply(lambda x: user_map[x])