A stupidly intelligent-ish Rock Paper Scissors program

rps.py

#!/usr/bin/python3
# vim: fileencoding=utf8:filetype=python:nu:expandtab

# Updated for 3.10 / 3.11

__all__ = ['getUserChocie', 'playForever']

from typing import Any, Literal, Optional
from collections.abc import Callable, Iterable

from random import randrange

# A utility function to prompt the user for a choice.
# Type hinting needs improvements to properly work.
def getUserChoice(
    choices: dict[str, Any],
    prompt: str = '',
    /, *,
    mapfunc: Optional[Callable[[str], str | None]] = None,
    clear: Literal['always', 'once', 'never'] = 'never',
    cleartext: str = '\033[H\033[2J',
) -> Any:
    if clear == 'once':
        print(cleartext, end='', flush=True)
    elif clear == 'always':
        prompt = cleartext + prompt
    inp: Optional[str] = None
    while True:
        inp: str = input(prompt)
        if mapfunc is not None:
            inp = mapfunc(inp)
            if inp is None:
                continue
        if inp in choices:
            return choices[inp]



# Helper function for my main loop below.
def toLowerAndStrip(text: str, /) -> str:
    return text.strip().lower()



def multiMapDict(entries: Iterable, /) -> dict:
    result = {}
    for value, *keys in entries:
        for key in keys:
            result[key] = value
    return result



# Main loop.
# tuple returned: (total, wins, losses, ties)
def playForeverRPS() -> tuple[int, int, int, int]:

    # The constants for this function.

    # For the display side as well as for
    # the automatic picking by the CPU by
    # checking its length.
    CHOICE_NAMES: tuple[str, ...] = ('Rock', 'Paper', 'Scissors')

    # This is the mapping used for when
    # asking the player for a choice.
    # 'None' is being used to single
    # that the player is done playing.
    # The others must be a valid index
    # to CHOICE_NAMES above.
    CHOICE_MAPPING: dict[str, int | None] = multiMapDict((
        (0, 'r', 'rock'),
        (1, 'p', 'paper'),
        (2, 's', 'scissors', 'scissor'),
        (None, 'q', 'quit')
    ))

    PROMPT: str = '''\
Win/Loss/Draw: {win}/{loss}/{draw}
Total: {total}
    {you_msg}{you_pick}
    {cpu_msg}{cpu_pick}
    {out_msg}
Pick your choice:
  [R]ock,  [P]aper,  [S]cissors
      [Q]uit
> '''

    # The mutable values for this function.

    # These two are plopped into the
    # 'PROMPT' template string while
    # 'stats' is also reused when
    # returning from this function.
    stats: dict[str, int] = {
        'win': 0, 'loss': 0,
        'draw': 0, 'total': 0
    }
    messages: dict[str, str] = {
        'you_msg': '', 'you_pick': '',
        'cpu_msg': '', 'cpu_pick': '',
        'out_msg': ''
    }

    # Assigning them here for type hints
    chosen: Optional[int] = None
    bot: int = 0
    while True:
        try:
            chosen = getUserChoice(
                CHOICE_MAPPING,
                PROMPT.format(**stats, **messages),
                mapfunc=toLowerAndStrip, # be a bit forgiving
                clear='always' # works best in *nix-like or PowerShell
            )
        #except KeyboardInterrupt as e:
        #    raise e
        except EOFError:
            # assume the use wanted to quit
            chosen = None
        if chosen is None:
            return stats['total'], stats['win'], stats['loss'], stats['draw']

        # pick the bot's choice
        bot = randrange(0, len(CHOICE_NAMES))

        # assign to the strings for who picked what
        messages['you_pick'] = CHOICE_NAMES[chosen]
        messages['cpu_pick'] = CHOICE_NAMES[bot]

        # On first time, add the strings in.
        # Also, increase the total played by 1.
        if not stats['total']:
            messages['you_msg'] = 'You picked: '
            messages['cpu_msg'] = 'CPU picked: '
        stats['total'] += 1

        # Assuming it was not altered ...
        # 0 = rock, 1 = paper, 2 = scissors
        match (chosen - bot + 3) % 3:
            case 0: # Tie
                messages['out_msg'] = ' == Tie Game =='
                stats['draw'] += 1
            case 1: # Win
                messages['out_msg'] = '== You Win! =='
                stats['win'] += 1
            case 2: # Loss
                messages['out_msg'] = '== You Lose =='
                stats['loss'] += 1



def main() -> int:
    from sys import argv
    outid = None
    # If any argument is specified, it is assumed to
    # be the file descriptor to use for the results.
    if len(argv) > 1:
        try:
            outid = int(argv[1])
        except ValueError:
            return 1 # Invalid input
    if outid is None:
        # No argument specified, just play and
        # ignore the results.
        playForeverRPS()
        return 0
    # It will error here if using STDIN or any
    # file descriptor that is not available.
    # Depending on the input, redirection or
    # pipe, it may even stack another error.
    try:
        with open(outid, 'w', closefd=False) as f:
            print(*playForeverRPS(), sep=' ', file=f)
    except KeyboardInterrupt:
        return 2
    except OSError:
        return 1 # Most likely the error stated above
    return 0



if __name__ == '__main__':
    main()