human
I found an interesting problem on https://leetcode.com/problems/design-twitter/:
Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user's news feed. Your design should support the following methods:


postTweet(userId, tweetId): Compose a new tweet.
getNewsFeed(userId): Retrieve the 10 most recent tweet ids in the user's news feed. Each item in the news feed must be posted by users who the user followed or by the user herself. Tweets must be ordered from most recent to least recent.
follow(followerId, followeeId): Follower follows a followee.
unfollow(followerId, followeeId): Follower unfollows a followee.


Example:

Twitter twitter = new Twitter();

// User 1 posts a new tweet (id = 5).
twitter.postTweet(1, 5);

// User 1's news feed should return a list with 1 tweet id -> [5].
twitter.getNewsFeed(1);

// User 1 follows user 2.
twitter.follow(1, 2);

// User 2 posts a new tweet (id = 6).
twitter.postTweet(2, 6);

// User 1's news feed should return a list with 2 tweet ids -> [6, 5].
// Tweet id 6 should precede tweet id 5 because it is posted after tweet id 5.
twitter.getNewsFeed(1);

// User 1 unfollows user 2.
twitter.unfollow(1, 2);

// User 1's news feed should return a list with 1 tweet id -> [5],
// since user 1 is no longer following user 2.
twitter.getNewsFeed(1);

I tried it in Python, but could not do it. Can you solve it?

 What is a the Python program you requested?
assistant
#Here is the Python program you requested.

class Twitter:
 
     def __init__(self):
         """
         Initialize your data structure here.
         """
         # e.g. [{"user1":"tweet1"}, {"user2":"tweet2"},...] - fast tweets access
         self.tweets = []
         
         # e.g. {"user1":[0,2,4,5], "user2":[1,3]} - fast user-tweets access
         self.userTweets = {}
         
         # e.g. {"user1":[0,1,2,3,4,5]}
         self.feeds = {}
         
         # e.g. {user2:[1]}
         self.followers = {}
         self.followees = {}
         # eg. {(user1,user2):True}
         self.relations = {}
 
     def postTweet(self, userId, tweetId):
         """
         Compose a new tweet.
         :type userId: int
         :type tweetId: int
         :rtype: void
         """
         # create tweet
         self.tweets.append({"userId":userId, "tweetId":tweetId})
         lastIndex = len(self.tweets)-1
         
         # create user tweet list
         if userId not in self.userTweets:
             self.userTweets[userId] = []
         self.userTweets[userId].append(lastIndex)
         
         # update feeds
         followers = self.followers.get(userId, [])
         for followerId in [userId]+followers:
             # add tweet, reverse sort, cut recent 10
             self.feeds[followerId] = ([tweetId] + self.feeds.get(followerId, []))[:10]
 
     def getNewsFeed(self, userId):
         """
         Retrieve the 10 most recent tweet ids in the user's news feed. Each item in the news feed must be posted by users who the user followed or by the user herself. Tweets must be ordered from most recent to least recent.
         :type userId: int
         :rtype: List[int]
         """
         return self.feeds.get(userId, [])
         
 
     def follow(self, followerId, followeeId):
         """
         Follower follows a followee. If the operation is invalid, it should be a no-op.
         :type followerId: int
         :type followeeId: int
         :rtype: void
         """        
         # no-op case
         if (followerId,...