mastermind: guess the color code

rc_mastermind.py

import random

def is_win(g, s):
  '''check for a win, assign win value, return boolean'''
  if all(g[i] == s[i] for i in range(len(s))):
    win = True
    print(f'You won! The code was {s}')
    return win
  else:
    win = False
    return win

def valid_max(max_g):
  '''check if the max chosen is int > 0'''
  if type(max_g) == int and max_g > 0:
    return True
  else:
    return False

def play():
  '''play mastermind'''
  print('*****\nFour stones are lined up in a color code: guess the code!\n(The colors don\'t have to all be different.)\n\nhints:\nb = right color, right spot\nw = right color, wrong spot\n*****\n')
  n_guess = 1
  win = False
  n_code = 4
  colors = list('roygbp')
  s = [random.choice(colors) for _ in range(n_code)]
  valid_max = False
  while valid_max == False:
    try:
      max_g = int(input('Max # guesses (int > 0): '))
      # check if guess in colors and len 4
      if max_g > 0:
        valid_max = True
      else:
        print('Invalid max.')
    except:
      print('Invalid max.')
  while n_guess <= max_g and win == False:
    valid_guess = False
    print(f'Guess {n_guess} of {max_g}')
    while valid_guess == False:  
      g = list(input(f'{len(s)} colors from {colors}:\n').lower())
      if len(g) == len(s) and all(g[i] in colors for i in range(len(g))):
        valid_guess = True
      else:
        print(f'Not a valid guess')
    n_guess += 1
    win = is_win(g, s)
    if win == True:
      return
    # check for any color + position matches: these are black pins
    matches = []
    match_i = [] 
    nbp = 0
    for i in range(len(g)):
      if g[i] == s[i]:
        matches.append((i, s[i]))
        nbp += 1
    # check for color-only matches: these are black pins (don't double count)
    nwp = 0
    match_i = [i for (j, (i, val)) in enumerate(matches)]
    valid_i = list(range(len(g)))
    for i in match_i:
      valid_i.remove(i)
    valid_j = valid_i[:]
    for i in valid_i:
      for j in valid_j:
        if i != j:
          if g[i] == s[j]:
            nwp += 1
            valid_j.remove(j)
            break
    print(f'black: {nbp}, white: {nwp}')
  if win == False:
    print(f'Sorry! The code was {s}')

if __name__ == "__main__":
  play()