word permutations

permute_words.py

import collections
import dataclasses
import sys
from typing import Iterable, Self


IGNORED_WORDS: frozenset[str] = frozenset([
    'adv',
    'dis',
    'eds',
    'gad',
    'med',
])

# mega, mage


@dataclasses.dataclass(frozen=True)
class Components:
    counts: tuple[tuple[str, int], ...]

    @classmethod
    def from_str(cls, s: str) -> Self:
        counts: dict[str, int] = collections.defaultdict(int)
        for c in s:
            counts[c] += 1
        return cls(tuple(sorted(counts.items())))

    def __le__(self, other: 'Components') -> bool:
        i = iter(other.counts)
        for l, lcount in self.counts:
            for r, rcount in i:
                if l == r:
                    break
            else:
                return False
            if lcount > rcount:
                return False
        return True


Dictionary = dict[Components, set[str]]

def load_dictionary(path: str) -> Dictionary:
    dictionary: dict[Components, set[str]] = collections.defaultdict(set)
    with open(path, 'rt') as f:
        for line in f:
            word = line.strip()
            if len(word) >= 3 and word not in IGNORED_WORDS:
                dictionary[Components.from_str(word)].add(word)
    return dictionary


def find_words(dictionary: Dictionary, available: Components) -> Iterable[str]:
    for components, words in dictionary.items():
        if components <= available:
            yield from words


def print_words(dictionary: Dictionary, available: Components):
    for word in sorted(find_words(dictionary, available)):
        print(word)


def main(argv):
    dictionary = load_dictionary('/usr/share/dict/words')
    if len(argv) > 1:
        available = Components.from_str(''.join(argv[1:]))
        print_words(dictionary, available)
    else:
        while True:
            try:
                word = input('> ')
            except EOFError:
                return
            available = Components.from_str(word.strip())
            print_words(dictionary, available)

if __name__ == '__main__':
    main(sys.argv)