Python 2.7 and 3.5+ are supported.

We support the Japanese version of mahjong only (riichi mahjong).

Riichi mahjong hands calculation

This library can calculate hand cost (han, fu with details, yaku, and scores) for riichi mahjong (Japanese version).

It supports optional features like:

Feature	Keyword parameter	Default value
Disable or enable open tanyao yaku	has_open_tanyao	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Disable or enable aka dora in the hand	has_aka_dora	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Disable or enable double yakuman (like suuanko tanki)	has_double_yakuman	True
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Settings for different kazoe yakuman calculation (it сan be an yakuman or a sanbaiman)	kazoe_limit	HandConstants.KAZOE_LIMITED
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Support kiriage mangan	kiriage	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Allow to disable additional +2 fu in open hand (you can make 1-20 hand with that setting)	fu_for_open_pinfu	True
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Disable or enable pinfu tsumo	fu_for_pinfu_tsumo	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Counting renhou as 5 han or yakuman	renhou_as_yakuman	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Disable or enable Daisharin yakuman	has_daisharin	False
------------------------------------------------------------------------------------------	-------------------------	---------------------------
Disable or enable Daisharin in other suits (Daisuurin, Daichikurin)	has_daisharin_other_suits	False

The code was validated on tenhou.net phoenix replays in total on 11,120,125 hands.

So, we can say that our hand calculator works the same way that tenhou.net hand calculation.

Project repository: https://github.com/MahjongRepository/mahjong

How to install

pip install mahjong

How to use

You can find more examples here: https://github.com/MahjongRepository/mahjong/blob/master/doc/examples.py

Let's calculate how much will cost this hand:

Tanyao hand by ron

from mahjong.hand_calculating.hand import HandCalculator
from mahjong.tile import TilesConverter
from mahjong.hand_calculating.hand_config import HandConfig
from mahjong.meld import Meld

calculator = HandCalculator()

# we had to use all 14 tiles in that array
tiles = TilesConverter.string_to_136_array(man='22444', pin='333567', sou='444')
win_tile = TilesConverter.string_to_136_array(sou='4')[0]

result = calculator.estimate_hand_value(tiles, win_tile)

print(result.han, result.fu)
print(result.cost['main'])
print(result.yaku)
for fu_item in result.fu_details:
    print(fu_item)

Output:

1 40
1300
[Tanyao]
{'fu': 30, 'reason': 'base'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 2, 'reason': 'open_pon'}

How about tsumo?

result = calculator.estimate_hand_value(tiles, win_tile, config=HandConfig(is_tsumo=True))

print(result.han, result.fu)
print(result.cost['main'], result.cost['additional'])
print(result.yaku)
for fu_item in result.fu_details:
    print(fu_item)

Output:

4 40
4000 2000
[Menzen Tsumo, Tanyao, San Ankou]
{'fu': 20, 'reason': 'base'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 2, 'reason': 'tsumo'}

What if we add open set?

melds = [Meld(meld_type=Meld.PON, tiles=TilesConverter.string_to_136_array(man='444'))]

result = calculator.estimate_hand_value(tiles, win_tile, melds=melds, config=HandConfig(options=OptionalRules(has_open_tanyao=True)))

print(result.han, result.fu)
print(result.cost['main'])
print(result.yaku)
for fu_item in result.fu_details:
    print(fu_item)

Output:

1 30
1000
[Tanyao]
{'fu': 20, 'reason': 'base'}
{'fu': 4, 'reason': 'closed_pon'}
{'fu': 2, 'reason': 'open_pon'}
{'fu': 2, 'reason': 'open_pon'}

Shanten calculation

from mahjong.shanten import Shanten

shanten = Shanten()
tiles = TilesConverter.string_to_34_array(man='13569', pin='123459', sou='443')
result = shanten.calculate_shanten(tiles)

print(result)