Design Twitter Python Solution with Tests

lcpy gen -n 355   # by problem number
lcpy gen -s design_twitter   # by problem name

Input
["Twitter", "postTweet", "getNewsFeed", "follow", "postTweet", "getNewsFeed", "unfollow", "getNewsFeed"]
[[], [1, 5], [1], [1, 2], [2, 6], [1], [1, 2], [1]]
Output
[null, null, [5], null, null, [6, 5], null, [5]]

Explanation
Twitter twitter = new Twitter();
twitter.postTweet(1, 5); // User 1 posts a new tweet (id = 5).
twitter.getNewsFeed(1);  // User 1's news feed should return a list with 1 tweet id -> [5]. return [5]
twitter.follow(1, 2);    // User 1 follows user 2.
twitter.postTweet(2, 6); // User 2 posts a new tweet (id = 6).
twitter.getNewsFeed(1);  // 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.unfollow(1, 2);  // User 1 unfollows user 2.
twitter.getNewsFeed(1);  // User 1's news feed should return a list with 1 tweet id -> [5], since user 1 is no longer following user 2.

import heapq


class Twitter:
    def __init__(self) -> None:
        self.tweets: dict[int, list[tuple[int, int]]] = {}
        self.following: dict[int, set[int]] = {}
        self.timestamp = 0

    # Time: O(1)
    # Space: O(1)
    def post_tweet(self, user_id: int, tweet_id: int) -> None:
        self.timestamp += 1
        self.tweets.setdefault(user_id, []).append((self.timestamp, tweet_id))

    # Time: O(F * T log(F * T)) where F = followee count, T = tweets per user (bounded by 10)
    # Space: O(F * 10)
    def get_news_feed(self, user_id: int) -> list[int]:
        followees = self.following.get(user_id, set()) | {user_id}
        heap: list[tuple[int, int]] = []
        for followee in followees:
            # Only the 10 most recent per user can ever appear in the top-10 feed
            for time, tweet_id in self.tweets.get(followee, [])[-10:]:
                heapq.heappush(heap, (time, tweet_id))
                if len(heap) > 10:
                    heapq.heappop(heap)
        heap.sort(reverse=True)
        return [tweet_id for _, tweet_id in heap]

    # Time: O(1)
    # Space: O(1)
    def follow(self, follower_id: int, followee_id: int) -> None:
        if follower_id == followee_id:
            return
        self.following.setdefault(follower_id, set()).add(followee_id)

    # Time: O(1)
    # Space: O(1)
    def unfollow(self, follower_id: int, followee_id: int) -> None:
        self.following.get(follower_id, set()).discard(followee_id)