<p>尝试在每次运行后将数据保存到磁盘,并在下次运行前读取if back:</p>
<pre><code>import os.path
if not os.path.exists("mydatabase.txt"):
# initialize
user_ids=["Vishnu"]
user_ratings=[3.5]
else:
# read previous data from database file
user_ids=[]
user_ratings=[]
with open("mydatabase.txt", "r") as databasefile:
for line in databasefile:
userid, rating_str = line.split()
rating = float(rating_str)
user_ids.append(userid)
user_ratings.append(rating)
print("Welcome to Movie Predictor")
print("Enter your user id: ")
username=input()
print("Signing in...Please Wait!")
if username in user_ids:
user_index=user_ids.index(username)
avg_rating=user_ratings[user_index]
new_user=0
else:
user_ids.append(username)
user_ratings.append(3.5)
avg_rating=3.5
new_user=1
print("Current user ids: %s" % user_ids)
print("Current user ratings: %s" % user_ratings)
# write data to database file
with open("mydatabase.txt", "w") as databasefile:
for userid, rating in zip(user_ids, user_ratings):
databasefile.write("%s %.1f\n" % (userid, rating))
</code></pre>