Python Caesar密码解码器

感谢出色的Cristian Ciupitu，我的最终解决方案行之有效。

x = input()NUM_LETTERS = 26 #Can't import modules I'm using a web based grader/compilerdef SpyCoder(S, N):   y = ""   for i in S:      if(i.isupper()):         x = ord(i)         x += N         if x > ord('Z'): x -= NUM_LETTERS         elif x < ord('A'): x += NUM_LETTERS         y += chr(x)      else:         y += " "   return ydef GoodnessFinder(S):   y = 0   for i in S:      if i.isupper():         x = ord(i)         x -= ord('A')         y += letterGoodness[x]      else:         y += 1   return ydef GoodnessComparer(S):   goodnesstocompare = GoodnessFinder(S)   goodness = 0   v = ''   best_v = S   for i in range(0, 26):     v = SpyCoder(S, i)     goodness = GoodnessFinder(v)     if goodness > goodnesstocompare:         best_v = v         goodnesstocompare = goodness   return best_vprint(GoodnessComparer(x))

多谢您的协助！