text: import pandas as pd
  import numpy as np
  import matplotlib.pylab as plt 
  
  # read data
  u_cols = ['user_id', 'age', 'sex', 'occupation', 'zip_code']
  users = pd.read_csv('ml-100k/u.user', sep='|', names=u_cols,encoding='latin-1')
  
  r_cols = ['user_id', 'movie_id', 'rating', 'unix_timestamp']
  ratings = pd.read_csv('ml-100k/u.data', sep='\t', names=r_cols,encoding='latin-1')
  
  m_cols = ['movie_id', 'title', 'release_date', 'video_release_date', 'imdb_url'] 
  movies = pd.read_csv('ml-100k/u.item', sep='|', names=m_cols, usecols=range(5),encoding='latin-1') 
  
  # data merge
  movie_ratings = pd.merge(movies, ratings) 
  lens = pd.merge(movie_ratings, users)
  print(lens.head())