Python 3.7
尝试制作数字猜谜游戏。这是我的代码：
#This is the guess the number game!
import random
secretNumber = random.randint(0,20)
print('I am thinking of a secret number between 0 and 20, can you guess what it is in six tries or less?')
for guessTimes in range(1,7):
try:
guessNumber = int(input())
print(type(guessNumber))
print('Guess Number: ' +str(guessNumber))
except ValueError:
guessNumber = None
print('Secret Number: ' +str(secretNumber))
print('You have to give me a valid integer for your guess.', end = ' ')
if guessNumber and guessNumber < secretNumber:
print('You have guessed a number that is too low...')
elif guessNumber and guessNumber > secretNumber:
print('You have guessed a number that is too high...')
elif guessNumber and guessNumber == secretNumber:
print('Great job, you guessed the secret number in only ' +str(guessTimes)+ ' tries!')
print('You should go PRO!')
break
if guessTimes > 6:
print('Sorry, that was six tries and lots of fail, better luck next time!')
elif guessTimes == 1:
print('That is ' +str(guessTimes)+ ' failed attempt thus far, you have ' +str(6-guessTimes)+ ' chances remaining. Please try again.')
elif guessTimes > 1:
print('That is ' +str(guessTimes)+ ' failed attempts thus far, you have ' +str(6-guessTimes)+ ' chances remaining. Please try again.')
guessTimes += 1
continue
对于所有介于1和123,412,351之间的guessNumber值，这一切似乎都可以正常工作。但是由于某种原因，每当我输入0作为guessNumber时，代码都会跳过该行：
if guessNumber and guessNumber < secretNumber:
print('You have guessed a number that is too low...')
很抱歉，这不是一个超级相关的问题，但是我已经将我的头撞了好一阵子了，无法弄清楚为什么当guessNumber ==时，该行的计算结果不为True 0。
答案 0 :(得分：1)
flutterEngine?.run(withEntrypoint: nil)和None在Python中都是“虚假的”，因此测试0时if guessNumber and guessNumber < secretNumber:会短路，因为它是guessNumber和0是虚假的。
您需要缩小支票的范围，使其仅捕获0，并将测试形式从None更改为if guessNumber and ...:。
另一种解决方案是避免在给出无效值时完全检查猜测。通过从if guessNumber is not None and ...: / try扩展到except / try / except，您可以相当容易地做到这一点：
else这里的优点是，您完全不用理会for guessTimes in range(1,7):
try:
guessNumber = int(input())
print(type(guessNumber))
print('Guess Number: ' +str(guessNumber))
except ValueError:
print('Secret Number: ' +str(secretNumber))
print('You have to give me a valid integer for your guess.', end = ' ')
else:
# Only run when no ValueError occurs
if guessNumber < secretNumber:
print('You have guessed a number that is too low...')
elif guessNumber > secretNumber:
print('You have guessed a number that is too high...')
elif guessNumber == secretNumber:
print('Great job, you guessed the secret number in only ' +str(guessTimes)+ ' tries!')
print('You should go PRO!')
break
if guessTimes == 1:
print('That is ' +str(guessTimes)+ ' failed attempt thus far, you have ' +str(6-guessTimes)+ ' chances remaining. Please try again.')
else:
print('That is ' +str(guessTimes)+ ' failed attempts thus far, you have ' +str(6-guessTimes)+ ' chances remaining. Please try again.')
else:
# Run when loop exits without break
print('Sorry, that was six tries and lots of fail, better luck next time!')
处于垃圾状态时（不必使用guessNumber作为标志值之类的东西），因此，当它不是垃圾时，您可以完全不需要检查None的标志。
旁注：在新代码中，我删除了None和guessTimes += 1，因为continue已经为您完成了递增操作，而for i in range(1, 7):作为循环中的最后一条语句是荒谬的。我还将“太多的猜测”输出移到了continue循环的else上；您将永远不会按原样写该代码（因为循环以for以guessTimes结尾，6始终为false），并且它保存检查以确保在循环结束时没有guessTimes > 6。
答案 1 :(得分：0)
如果在条件语句（如if中使用数字，则将其视为boolean（如果为0，则为false，否则为true）
if guessNumber and guessNumber < secretNumber:
print('You have guessed a number that is too low...')
在if语句中有两个条件，第一个条件为false，因为输入0的guessNumber为false，因此该行被跳过。
从条件中删除guessNumber，您就很好
if guessNumber < secretNumber:
print('You have guessed a number that is too low...')