python3: Échec de chargement de jeu de données MovieLens: KeyError: '1'

Question

je lis l'exemple dans le livre Programming.Collective.Intelligence et ne savent pas pourquoi il y a une KeyError ...

u.item

movie_id | title | ... 

1|Toy Story (1995)|... 
2|GoldenEye (1995)|... 
... 

u.data

user movieid rating timestamp 
196 242 3 881250949 
186 302 3 891717742 
... 

Code

def loadMovieLens(path='E:/project/datamining/collective/chapter2/ml-100k'): 
    # Get movie titles 
    movies = {} 
    for line in open(path+'/u.item', encoding='utf-8'): 
     (id, title) = line.split('|')[0:2] 
     movies[id] = title 
    # load data 

    prefs = {} 
    for line in open(path+'/u.data',encoding='utf-8'): 
     (user,movieid,rating,ts)=line.split('\t') 
     prefs.setdefault(user,{}) 
     prefs[user][movies[movieid]] = float(rating) 
    return prefs 
prefs = loadMovieLens() 

---

Traceback (most recent call last): 
File "E:\project\datamining\collective\chapter2\recommendations.py", line 181, in <module> 
    prefs = loadMovieLens() 
File "E:\project\datamining\collective\chapter2\recommendations.py", line 179, in loadMovieLens 
    prefs[user][movies[movieid]] = rating 
KeyError: '1' 

Answer 1

gestion des erreurs d'essai. quelque chose comme:

errors = 0 
    for line in open(path + '/ratings.txt'): 
     try: 
      (user, movieid, rating, ts) = line.split('\t') 
      prefs.setdefault(user, {}) 
      prefs[user][movies[movieid]] = float(rating) 
     except KeyError: 
      errors+=1 

    return prefs