我正在努力编一本对狗有好有坏的食物的字典

Question

我在让它打印列表中每个项目的响应时遇到了一个问题，但是如果我去掉了负责的循环，我就无法检查用户输入，例如，如果他们输入“almond”，它会说它不知道，因为在我的列表中，它说的是“almonds”

这就是我对每个元素进行循环的原因，因此它将在元素中搜索单词，但循环打印出它无法找到答案几次（不必要！），然后是答案

我希望这是可以理解的，以下是我的代码：

good = ['bread','cashews','cheese','coconut']
bad = ['almonds','chocolate','cinnamon']
def check(food):
  for b,g in zip(bad,good):
    if food.lower() in g:
      print(f'Yes, dogs can eat {food}.')
      break
    elif food.lower() in b:
      print(f'No, dogs cannot eat {food}.')
      break
    else:
      print(f'{food} is not in my dictionary yet. My apologies.')

while True:
  f = str(input('What food would you like to check?: '))
  check(f)

Answer 1

您可以使用这种简单的pythonic方法并摆脱循环：

def check(food):
    if any(list(map(lambda g: food.lower() in g, (g for g in good)))):
        print(f'Yes, dogs can eat {food}.')
    elif any(list(map(lambda b: food.lower() in b, (b for b in bad)))):
        print(f'No, dogs cannot eat {food}.')
    else:
      print(f'{food} is not in my dictionary yet. My apologies.')

Answer 2

您需要分别循环浏览这两个列表：

good = ['bread','cashews','cheese','coconut']
bad = ['almonds','chocolate','cinnamon']

def check(food):
    for g in good:
        if food.lower() in g:
            print(f'Yes, dogs can eat {food}.')
            return None
    for b in bad:
        if food.lower() in b:
            print(f'No, dogs cannot eat {food}.')
            return None
    else:
        print(f'{food} is not in my dictionary yet. My apologies.')
        return None

while True:
    f = str(input('What food would you like to check?: '))
    check(f)

添加return语句非常重要，因此函数会在满足条件的地方停止，如果删除return语句，它将始终打印最后一行。（您也可以使用break，但我更喜欢return）

Answer 3

您不需要zip（）函数，并且需要一个return而不是break来结束函数。另外，我建议您添加一个退出条件，以便可以停止while循环

以下是我的建议：

good = ['bread','cashews','cheese','coconut']
bad = ['almonds','chocolate','cinnamon']

def check(food):
    if food.lower() in good:
        print(f'Yes, dogs can eat {food}.')
    elif food.lower() in bad:
        print(f'No, dogs cannot eat {food}.')
    else:
        print(f'{food} is not in my dictionary yet. My apologies.')
    return

while True:
    f = str(input('What food would you like to check?: '))
    if f == 'exit':
        break
    check(f)

输出：

What food would you like to check?: almond
almond is not in my dictionary yet. My apologies.
What food would you like to check?: almonds
No, dogs cannot eat almonds.
What food would you like to check?: exit