Wordiff

Wordiff is a new game in which contestants take turns spelling new dictionary words that only differ from the last by a change in one letter.

Wordiff is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

The change can be either:

1. a deletion of one letter;
2. addition of one letter;
3. or change in one letter.

Note:

• All words must be in the dictionary.
• No word in a game can be repeated.
• The first word must be three or four letters long.

Task

Create a program to aid in the playing of the game by:

• Asking for contestants names.
• Chosing an initial random three or four letter word from the dictionary.
• Asking each contestant in their turn for a wordiff word.
• Checking the wordiff word is:

• in the dictionary,
• not a repetition of past words,
• and differs from the last appropriately.

Optional stretch goal

Add timing.

• Allow players to set a maximum playing time for the game.
• An internal timer accumulates how long each user takes to respond in their turns.
• Play is halted if the maximum playing time is exceeded on a players input.

• That last player must have entered a wordiff or looses.
• If the game is timed-out, the loser is the person who took the longest `average` time to answer in their rounds.

Python

This is without timing, but ends by showing some wordiffs from the dictionary that could have worked on failure. <lang python># -*- coding: utf-8 -*-

from typing import List, Tuple, Dict, Set from itertools import cycle, islice from collections import Counter import re import random import urllib

dict_fname = 'unixdict.txt' dict_url1 = 'http://wiki.puzzlers.org/pub/wordlists/unixdict.txt' # ~25K words dict_url2 = 'https://raw.githubusercontent.com/dwyl/english-words/master/words.txt' # ~470K words

word_regexp = re.compile(r'^[a-z]{3,}$') # reduce dict words to those of three or more a-z characters.

def load_dictionary(fname: str=dict_fname) -> Set[str]:

   "Return appropriate words from a dictionary file"
   with open(fname) as f:
       return {lcase for lcase in (word.strip().lower() for word in f)
               if word_regexp.match(lcase)}

def load_web_dictionary(url: str) -> Set[str]:

   "Return appropriate words from a dictionary web page"
   words = urllib.request.urlopen(url).read().decode().strip().lower().split()
   return {word for word in words if word_regexp.match(word)}

def get_players() -> List[str]:

   "Return inputted ordered list of contestant names."
   names = input('Space separated list of contestants: ')
   return [n.capitalize() for n in names.strip().split()]

def is_wordiff(wordiffs: List[str], word: str, dic: Set[str], comment=True) -> bool:

   "Is word a valid wordiff from wordiffs[-1] ?"
   if word not in dic:
       if comment: 
           print('That word is not in my dictionary')
       return False
   if word in wordiffs:
       if comment: 
           print('That word was already used.')
       return False
   if len(word) < len(wordiffs[-1]):
       return is_wordiff_removal(word, wordiffs[-1], comment)
   elif len(word) > len(wordiffs[-1]):
       return is_wordiff_insertion(word, wordiffs[-1], comment)
   
   return is_wordiff_change(word, wordiffs[-1], comment)

def is_wordiff_removal(word: str, prev: str, comment=True) -> bool:

   "Is word derived from prev by removing one letter?"
   ...
   ans = word in {prev[:i] + prev[i+1:] for i in range(len(prev))}
   if not ans:
       if comment: 
           print('Word is not derived from previous by removal of one letter.')
   return ans

def is_wordiff_insertion(word: str, prev: str, comment=True) -> bool:

   "Is word derived from prev by adding one letter?"
   diff = Counter(word) - Counter(prev)
   diffcount = sum(diff.values())
   if diffcount != 1:
       if comment: 
           print('More than one character insertion difference.')
       return False
   
   insert = list(diff.keys())[0] 
   ans =  word in {prev[:i] + insert + prev[i:] for i in range(len(prev) + 1)}
   if not ans:
       if comment: 
           print('Word is not derived from previous by insertion of one letter.')
   return ans

def is_wordiff_change(word: str, prev: str, comment=True) -> bool:

   "Is word derived from prev by changing exactly one letter?"
   ...
   diffcount = sum(w != p for w, p in zip(word, prev))
   if diffcount != 1:
       if comment: 
           print('More or less than exactly one character changed.')
       return False
   return True

def could_have_got(wordiffs: List[str], dic: Set[str]):

   return (word for word in (dic - set(wordiffs)) 
           if is_wordiff(wordiffs, word, dic, comment=False))

if __name__ == '__main__':

   dic = load_web_dictionary(dict_url2)
   dic_3_4 = [word for word in dic if len(word) in {3, 4}]
   start = random.choice(dic_3_4)
   wordiffs = [start]
   players = get_players()
   for name in cycle(players):
       word = input(f"{name}: Input a wordiff from {wordiffs[-1]!r}: ").strip()
       if is_wordiff(wordiffs, word, dic):
           wordiffs.append(word)
       else:
           print(f'YOU HAVE LOST {name}!')
           print("Could have used:", 
                 ', '.join(islice(could_have_got(wordiffs, dic), 10)), '...')
           break</lang>

Output:

Space separated list of contestants: Paddy Maggie

Paddy: Input a wordiff from 'sett': sets

Maggie: Input a wordiff from 'sets': bets

Paddy: Input a wordiff from 'bets': buts

Maggie: Input a wordiff from 'buts': bits

Paddy: Input a wordiff from 'bits': bit

Maggie: Input a wordiff from 'bit': bite

Paddy: Input a wordiff from 'bite': biter

Maggie: Input a wordiff from 'biter': bitter

Paddy: Input a wordiff from 'bitter': sitter

Maggie: Input a wordiff from 'sitter': titter

Paddy: Input a wordiff from 'titter': tutter
That word is not in my dictionary
YOU HAVE LOST Paddy!
Could have used: titfer, witter, tittery, totter, titler, kitter, twitter, tilter, gitter, jitter ...