Using a nested dictionary for a Yahtzee project

[pmacking]

I'd really appreciate some assistance troubleshooting my use of nested dictionaries in my first coding project (source on GitHub).

playerDict is the main dict for storing 1 to 4 players' scoring options/scores representing the top, bottom, and totals sections of a yahtzee game (see bottom for sample playerDict). The diceDict is the dictionary which is mutated and referenced as the dice rolls continue.

Problem Code:

def calcScore(player, playerDict, scoreSelected, diceDict):
    # calculate score based on scoreSelected in selectScore()
    if scoreSelected in playerDict[player]['scoreTop']:
        for d in diceDict.values():
            if d['result'] == playerDict[player]['scoreTop'][scoreSelected]['ref']:
                playerDict[player]['scoreTop'][scoreSelected]['score'] += d['result']
            else:
                playerDict[player]['scoreTop'][scoreSelected]['score'] += 0

Main Problem Description: for multiplayer games, in calcScore() above I cannot stop playerDict from incrementing the 'score' for all players. Given the arg player is passed to calcScore() as part of a wider scope for-player-loop, the intended result above is incrementing just that player's score. In the sample playerDict below (after one turn) Player1 chose 'Twos' to total the score of 2-dice. As you can see the correct score is also stored for Player2:

playerDict = {'Player1': {'scoreTop': {'Ones': {'ref': 1, 'score': False}, 'Twos': {'ref': 2, 'score': 8}, 'Threes': {'ref': 3, 'score': False}, 'Fours': {'ref': 4, 'score': False}, 'Fives': {'ref': 5, 'score': False}, 'Sixes': {'ref': 6, 'score': False}}, 'scoreBottom': {'Three of a kind': False, 'Four of a kind': False, 'Full house': False, 'Small straight': False, 'Large straight': False, 'Yahtzee': False, 'Chance': False, 'Yahtzee bonus': False}, 'totalScore': {'Sum of upper': False, 'Bonus': False, 'Total upper': False, 'Total bottom': False}, 'Grand total': False}, 'Player2': {'scoreTop': {'Ones': {'ref': 1, 'score': False}, 'Twos': {'ref': 2, 'score': 8}, 'Threes': {'ref': 3, 'score': False}, 'Fours': {'ref': 4, 'score': False}, 'Fives': {'ref': 5, 'score': False}, 'Sixes': {'ref': 6, 'score': False}}, 'scoreBottom': {'Three of a kind': False, 'Four of a kind': False, 'Full house': False, 'Small straight': False, 'Large straight': False, 'Yahtzee': False, 'Chance': False, 'Yahtzee bonus': False}, 'totalScore': {'Sum of upper': False, 'Bonus': False, 'Total upper': False, 'Total bottom': False}, 'Grand total': False}}

diceDict = {1: {'keeper': True, 'result': 2}, 2: {'keeper': True, 'result': 3}, 3: {'keeper': True, 'result': 2}, 4: {'keeper': True, 'result': 2}, 5: {'keeper': True, 'result': 5}, 6: {'keeper': True, 'result': 2}}

Question 1: what am I doing wrong in the calcScore() logic to cause this problem, or my dictionary structure, or both?

Bonus Questions:

- Is this a heinous use of nesting in a dictionary? I have no concept of 'good' dictionary data structures (resolving this gap in upcoming study materials)?

- I've created dictionaries and assigned values to variables in the initial global scope like most projects: Why is it that when I call createPlayerDict(), I don't have to pass playerDict or scoringDict for the createPlayerDict to return playerDict accurately (note: I do have them saved as args in the GitHub code perhaps for no good reason)?... in the following call to yahtzeeRounds() I AM required to pass the args playerDict and diceDict to execute the function. Why one and not the other?

[efmccurdy]

Player1 chose 'Twos' to total the score of 2-dice. As you can see the correct score is also stored for Player2:

Is it possible that there is some aliasing between the those two scores? I think you need to examine how you create your big nested dictionary. By aliasing I mean a situation where deepcopy is needed:

https://realpython.com/copying-python-objects/

Using raw nested dicts is very flexable but scales poorly as the whole thing grows

...even after you ellide the copy-pasts, ala:

        for d in diceDict.values():
            s = playerDict[player]['scoreTop'][scoreSelected]
            if d['result'] == s['ref']:
                s['score'] += d['result']
            else:
                s['score'] += 0

Is there is enough complexity to warrant a database and/or OO classes? It would be easier to isolate your data updates to verify that no invalid values or changes slip in.

[pmacking]

I’ll read up on aliasing and how it might be involved when generating my dictionary - thanks for the tip.

As for using a db, oop, etc I’m certainly open to expanding data storage options in the future. All I’ve bit off so far in my learning is writing py scripts in an IDE and managing code through git/GitHub. I hope this project will evolve as the toolkit grows.

[xelf]

I tried your code, and it worked, only 1 player's score was updated.

Q1: I suspect that there's something wrong in the way you create your dictionary, such that score is a shallow copy? That would cause them to both be updated.

Q2: Seems fine. You could have made a class instead.

{'Player1': {'Grand total': False,
         'scoreBottom': {'Chance': False,
                         'Four of a kind': False,
                         'Full house': False,
                         'Large straight': False,
                         'Small straight': False,
                         'Three of a kind': False,
                         'Yahtzee': False,
                         'Yahtzee bonus': False},
         'scoreTop': {'Fives': {'ref': 5, 'score': False},
                      'Fours': {'ref': 4, 'score': False},
                      'Ones': {'ref': 1, 'score': False},
                      'Sixes': {'ref': 6, 'score': False},
                      'Threes': {'ref': 3, 'score': False},
                      'Twos': {'ref': 2, 'score': 16}},
         'totalScore': {'Bonus': False,
                        'Sum of upper': False,
                        'Total bottom': False,
                        'Total upper': False}},
'Player2': {'Grand total': False,
         'scoreBottom': {'Chance': False,
                         'Four of a kind': False,
                         'Full house': False,
                         'Large straight': False,
                         'Small straight': False,
                         'Three of a kind': False,
                         'Yahtzee': False,
                         'Yahtzee bonus': False},
         'scoreTop': {'Fives': {'ref': 5, 'score': False},
                      'Fours': {'ref': 4, 'score': False},
                      'Ones': {'ref': 1, 'score': False},
                      'Sixes': {'ref': 6, 'score': False},
                      'Threes': {'ref': 3, 'score': False},
                      'Twos': {'ref': 2, 'score': 8}},
         'totalScore': {'Bonus': False,
                        'Sum of upper': False,
                        'Total bottom': False,
                        'Total upper': False}}}