Question

我正在尝试编写一个代码片段，将ID添加到集合中，这样我就可以看到它是否已被使用，并将该集合存储在一个文件中。我一直试图通过使用Shelve模块来做到这一点，但我遇到了一些麻烦。到目前为止，我有这个代码

import praw
import datetime
import shelve

user_agent ='Removed'
r = praw.Reddit(user_agent=user_agent)
submission = r.get_submission(submission_id='11v36o')
r.login('Removed','Removed')
files = shelve.open("PrawTest3.dat", writeback=True)
print "Opened!"
already_done = {} 
files["already_done"] = ["a","b"]
files.close()
done = set()
print "Running"

while True:
    subreddit = r.get_subreddit('mobilebot')
    all_comments = subreddit.get_comments()
    files = shelve.open("PrawTest2.dat", writeback=True)
    already_done = files["already_done"]
    files.close()
    for comment in all_comments:
        if (comment.body == "Hello") and (comment.id not in already_done) and (comment.id not in done):

            files = shelve.open("PrawTest2.dat", writeback=True)
            comment.reply(' world!')
            already_done = files["already_done"]
            already_done.append(comment.id)

            files[already_done] = already_done
            print "Shelves working"
            a = datetime.datetime.now()
            b = "%s:%s:%s" % (a.hour,a.minute, a.second)
            print "["+b+"]"+"Comment sent!"
            files.sync()
            files.close()

Answer 1

Python的列表不能用作shelve或dic的键，因为它没有哈希值。但我认为你的问题只是这一行的一个错字：

files[already_done] = already_done

我想你想要它

files["already_done"] = already_done

Answer 2

错误在于：

files[already_done] = already_done

python中的

list是可变的。可变类型不能用作字典中的键。在执行already_done之前，将列表files[already_done] = already_done转换为元组，它将正常工作。

这就是我的意思：

>>> a_dict = {}
>>> a_list = [1, 2, 3]
>>> a_dict[a_list] = "Hello"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unhashable type: 'list'


>>> a_tuple = tuple(a_list)
>>> a_dict[a_tuple] = "Hello"
>>> a_dict
{(1, 2, 3): 'Hello'}

但是，如果您只想让密钥成为字符串“already_done”而不是列表already_done，那么您应该这样做：

files['already_done'] = already_done

使用shelf时获取“TypeError：unhashable type：'list'”

2 个答案: