leaderboard

Leaderboards backed by Redis in Python.

Builds off ideas proposed in http://www.agoragames.com/blog/2011/01/01/creating-high-score-tables-leaderboards-using-redis/.

Installation

pip install leaderboard

Make sure your redis server is running! Redis configuration is outside the scope of this README, but check out the Redis documentation.

Usage

Creating a leaderboard

Be sure to require the leaderboard library:

from leaderboard.leaderboard import Leaderboard

Create a new leaderboard or attach to an existing leaderboard named 'highscores':

highscore_lb = Leaderboard('highscores')

Defining leaderboard options

The default options are as follows:

    DEFAULT_PAGE_SIZE = 25
    DEFAULT_REDIS_HOST = 'localhost'
    DEFAULT_REDIS_PORT = 6379
    DEFAULT_REDIS_DB = 0
    DEFAULT_MEMBER_DATA_NAMESPACE = 'member_data'
    DEFAULT_GLOBAL_MEMBER_DATA = False
    ASC = 'asc'
    DESC = 'desc'
    MEMBER_KEY = 'member'
    MEMBER_DATA_KEY = 'member_data'
    SCORE_KEY = 'score'
    RANK_KEY = 'rank'

You would use the option, order=Leaderboard.ASC, if you wanted a leaderboard sorted from lowest-to-highest score. You may also set the order option on a leaderboard after you have created a new instance of a leaderboard. The various ..._KEY options above control what data is returned in the hash of leaderboard data from calls such as leaders or around_me. Finally, the global_member_data option allows you to control whether optional member data is per-leaderboard (False) or global (True).

Ranking members in the leaderboard

Add members to your leaderboard using rank_member:

for index in range(1, 11):
  highscore_lb.rank_member('member_%s' % index, index)

You can call rank_member with the same member and the leaderboard will be updated automatically.

Get some information about your leaderboard:

highscore_lb.total_members()
10

highscore_lb.total_pages()
1

Get some information about a specific member(s) in the leaderboard:

highscore_lb.score_for('member_4')
4.0

highscore_lb.rank_for('member_4')
7

highscore_lb.rank_for('member_10')
1

Retrieving members from the leaderboard

Get page 1 in the leaderboard:

highscore_lb.leaders(1)

[{'member': 'member_10', 'score': 10.0, 'rank': 1}, {'member': 'member_9', 'score': 9.0, 'rank': 2}, {'member': 'member_8', 'score': 8.0, 'rank': 3}, {'member': 'member_7', 'score': 7.0, 'rank': 4}, {'member': 'member_6', 'score': 6.0, 'rank': 5}, {'member': 'member_5', 'score': 5.0, 'rank': 6}, {'member': 'member_4', 'score': 4.0, 'rank': 7}, {'member': 'member_3', 'score': 3.0, 'rank': 8}, {'member': 'member_2', 'score': 2.0, 'rank': 9}, {'member': 'member_1', 'score': 1.0, 'rank': 10}]

Add more members to your leaderboard:

for index in range(50, 96):
  highscore_lb.rank_member('member_%s' % index, index)

highscore_lb.total_pages()
3

Get an "Around Me" leaderboard page for a given member, which pulls members above and below the given member:

highscore_lb.around_me('member_53')

[{'member': 'member_65', 'score': 65.0, 'rank': 31}, {'member': 'member_64', 'score': 64.0, 'rank': 32}, {'member': 'member_63', 'score': 63.0, 'rank': 33}, {'member': 'member_62', 'score': 62.0, 'rank': 34}, {'member': 'member_61', 'score': 61.0, 'rank': 35}, {'member': 'member_60', 'score': 60.0, 'rank': 36}, {'member': 'member_59', 'score': 59.0, 'rank': 37}, {'member': 'member_58', 'score': 58.0, 'rank': 38}, {'member': 'member_57', 'score': 57.0, 'rank': 39}, {'member': 'member_56', 'score': 56.0, 'rank': 40}, {'member': 'member_55', 'score': 55.0, 'rank': 41}, {'member': 'member_54', 'score': 54.0, 'rank': 42}, {'member': 'member_53', 'score': 53.0, 'rank': 43}, {'member': 'member_52', 'score': 52.0, 'rank': 44}, {'member': 'member_51', 'score': 51.0, 'rank': 45}, {'member': 'member_50', 'score': 50.0, 'rank': 46}, {'member': 'member_10', 'score': 10.0, 'rank': 47}, {'member': 'member_9', 'score': 9.0, 'rank': 48}, {'member': 'member_8', 'score': 8.0, 'rank': 49}, {'member': 'member_7', 'score': 7.0, 'rank': 50}, {'member': 'member_6', 'score': 6.0, 'rank': 51}, {'member': 'member_5', 'score': 5.0, 'rank': 52}, {'member': 'member_4', 'score': 4.0, 'rank': 53}, {'member': 'member_3', 'score': 3.0, 'rank': 54}, {'member': 'member_2', 'score': 2.0, 'rank': 55}]

Get rank and score for an arbitrary list of members (e.g. friends) from the leaderboard:

highscore_lb.ranked_in_list(['member_1', 'member_62', 'member_67'])

[{'member': 'member_1', 'score': 1.0, 'rank': 56}, {'member': 'member_62', 'score': 62.0, 'rank': 34}, {'member': 'member_67', 'score': 67.0, 'rank': 29}]

Retrieve members from the leaderboard in a given score range:

highscore_lb.members_from_score_range(4, 19)

[{'member': 'member_10', 'score': 10.0, 'rank': 47}, {'member': 'member_9', 'score': 9.0, 'rank': 48}, {'member': 'member_8', 'score': 8.0, 'rank': 49}, {'member': 'member_7', 'score': 7.0, 'rank': 50}, {'member': 'member_6', 'score': 6.0, 'rank': 51}, {'member': 'member_5', 'score': 5.0, 'rank': 52}, {'member': 'member_4', 'score': 4.0, 'rank': 53}]

Retrieve a single member from the leaderboard at a given position:

highscore_lb.member_at(4)

{'member': 'member_92', 'score': 92.0, 'rank': 4}

Retrieve a range of members from the leaderboard within a given rank range:

highscore_lb.members_from_rank_range(1, 5)

[{'member': 'member_95', 'score': 95.0, 'rank': 1}, {'member': 'member_94', 'score': 94.0, 'rank': 2}, {'member': 'member_93', 'score': 93.0, 'rank': 3}, {'member': 'member_92', 'score': 92.0, 'rank': 4}, {'member': 'member_91', 'score': 91.0, 'rank': 5}]

Optional member data notes

If you use optional member data, the use of the remove_members_in_score_range or remove_members_outside_rank methods will leave data around in the member data hash. This is because the internal Redis method, zremrangebyscore, only returns the number of items removed. It does not return the members that it removed.

Leaderboard request options

You can pass various options to the calls leaders, all_leaders, around_me, members_from_score_range, members_from_rank_range and ranked_in_list. Valid options are:

• with_member_data - true or false to return the optional member data.
• page_size - An integer value to change the page size for that call.
• members_only - true or false to return only the members without their score and rank.
• sort_by - Valid values for sort_by are score and rank.

Conditionally rank a member in the leaderboard

You can pass a function to the rank_member_if method to conditionally rank a member in the leaderboard. The function is passed the following 5 parameters:

• member: Member name.
• current_score: Current score for the member in the leaderboard. May be nil if the member is not currently ranked in the leaderboard.
• score: Member score.
• member_data: Optional member data.
• leaderboard_options: Leaderboard options, e.g. 'reverse': Value of reverse option

def highscore_check(self, member, current_score, score, member_data, leaderboard_options):
  if (current_score is None):
    return True
  if (score > current_score):
    return True
  return False

highscore_lb.rank_member_if(highscore_check, 'david', 1337)
highscore_lb.score_for('david')

1337.0

highscore_lb.rank_member_if(highscore_check, 'david', 1336)
highscore_lb.score_for('david')

1337.0

highscore_lb.rank_member_if(highscore_check, 'david', 1338)
highscore_lb.score_for('david')

1338.0

Ranking a member across multiple leaderboards

highscore_lb.rank_member_across(['highscores', 'more_highscores'], 'david', 50000, str({'member_name': 'david'}))

Alternate leaderboard types

The leaderboard library offers 3 styles of ranking. This is only an issue for members with the same score in a leaderboard.

Default: The Leaderboard class uses the default Redis sorted set ordering, whereby different members having the same score are ordered lexicographically. As per the Redis documentation on Redis sorted sets, "The lexicographic ordering used is binary, it compares strings as array of bytes."

Tie ranking: The TieRankingLeaderboard subclass of Leaderboard allows you to define a leaderboard where members with the same score are given the same rank. For example, members in a leaderboard with the associated scores would have the ranks of:

| member     | score | rank |
-----------------------------
| member_1   | 50    | 1    |
| member_2   | 50    | 1    |
| member_3   | 30    | 2    |
| member_4   | 30    | 2    |
| member_5   | 10    | 3    |

The TieRankingLeaderboard accepts one additional option, ties_namespace (default: ties), when initializing a new instance of this class. Please note that in its current implementation, the TieRankingLeaderboard class uses an additional sorted set to rank the scores, so please keep this in mind when you are doing any capacity planning for Redis with respect to memory usage.

Competition ranking: The CompetitionRankingLeaderboard subclass of Leaderboard allows you to define a leaderboard where members with the same score will have the same rank, and then a gap is left in the ranking numbers. For example, members in a leaderboard with the associated scores would have the ranks of:

| member     | score | rank |
-----------------------------
| member_1   | 50    | 1    |
| member_2   | 50    | 1    |
| member_3   | 30    | 3    |
| member_4   | 30    | 3    |
| member_5   | 10    | 5    |

Performance Metrics

You can view performance metrics for the leaderboard library at the original Ruby library's page.

Ports

The following ports have been made of the leaderboard gem.

Officially supported:

• CoffeeScript: https://github.com/agoragames/leaderboard-coffeescript
• Python: https://github.com/agoragames/leaderboard-python
• Ruby: https://github.com/agoragames/leaderboard

Unofficially supported (they need some feature parity love):

• Java: https://github.com/agoragames/java-leaderboard
• PHP: https://github.com/agoragames/php-leaderboard
• Scala: https://github.com/agoragames/scala-leaderboard

Contributing to leaderboard

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
• Fork the project
• Start a feature/bugfix branch
• Commit and push until you are happy with your contribution
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the version or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright

Copyright (c) 2011-2018 Ola Mork, David Czarnecki. See LICENSE.txt for further details.