The program keep asking to "guess a letter"

start = input("Press enter/return to start, or enter Q to quit")
if start.lower() == 'q':
    break

# pick a random word
secret_word = random.choice(words)
bad_guesses = []
good_guesses = []

while len(bad_guesses) < 7 and len(good_guesses) != len(list(secret_word)):

    # draw guessed letters, spaces, and strikes
    for letter in secret_word:
        if letter in good_guesses:
            print(letter, end='')
        else:
            print('_',end='')

    print('')
    print('Strikes: {}/7'.format((len(bad_guesses))))

    # take guess
    guess = input("Guess a letter: ").lower()

    if len(guess) != 1:
        print("You can only guess one letter!")
        continue
    elif guess in bad_guesses or guess in good_guesses:
        print("You have already guessed that letter!")
        continue
    elif not guess.isalpha():
        print("You can only guess letters!")
        continue

    if guess in secret_word:
        good_guesses.append(guess)
        if len(good_guesses) == len(list(secret_word)):
            print("Woho! you guessed the word! the word was {}".format(secret_word))
            break

    else:
        bad_guesses.append(guess)


else:
    print("You didn't guess it! My secret word was {}".format(secret_word))