words.py

import random

with open("dict.txt", "r", encoding="utf-8") as f:
    words = f.read().split("\n")

bot = input("Play with a bot (Y/n)? ").lower() == "y"

print("Type \"exit\" to exit.")

lastword = None
while True:
    word = input("Your word: ").lower()
    while lastword is not None and lastword[-1] != word[0] or word not in words:
        if word == "exit":
            break
        if lastword is not None and lastword[-1] != word[0]:
            print("The word you typed isn't correct: it doesn't start with the last word's last letter "
                  f"({lastword[-1]})")
        if word not in words:
            print("The word you typed isn't correct: it isn't a valid word or it was already used")
        word = input("Your word: ").lower()
    if word == "exit":
        break
    words.pop(words.index(word))
    lastword = word.replace("ь", "").replace("ъ", "").replace("ы", "").replace("ё", "е")
    if bot:
        choices = [i for i in words if i[0] == lastword[-1]]
        if len(choices) == 0:
            print("You... won?")
            break
        choice = random.choice(choices)
        print(f"Bot's choice: {choice}")
        words.pop(words.index(choice))
        lastword = choice.replace("ь", "").replace("ъ", "").replace("ы", "").replace("ё", "е")