python - 如果在 for 循环中没有匹配项，如何打印出特定的消息

Question

我的问题是如果在 for 循环中没有匹配的东西，如何打印出来。例如:

a = {'store' : 'A', 'menu' : 'pizza', 'price' : 20000}
b = {'store' : 'B', 'menu' : 'chicken', 'price' : 18000}
c = {'store' : 'C', 'menu' : 'noodle', 'price' : 5000}
d = {'store' : 'D', 'menu' : 'sushi', 'price' : 15000}
e = {'store' : 'E', 'menu' : 'chicken', 'price' : 23000}
f = {'store' : 'F', 'menu' : 'pork', 'price' : 30000}

Total = [a, b, c, d, e, f]

l = input('what food?:  ')
p = int(input('how much you want to spend?  '))

for i in range(5):
    if Total[i]['menu'] == l and int(Total[i]['price']) <= p:
        print('menu', Total[i]['store'], 'price', Total[i]['price'])

循环后，如果没有这样的商店满足条件，我想打印出 'There is no store' .

Answer 1

只需添加一个 bool 值来检查是否找到了价格。

a = {'store' : 'A', 'menu' : 'pizza', 'price' : 20000}
b = {'store' : 'B', 'menu' : 'chicken', 'price' : 18000}
c = {'store' : 'C', 'menu' : 'noodle', 'price' : 5000}
d = {'store' : 'D', 'menu' : 'sushi', 'price' : 15000}
e = {'store' : 'E', 'menu' : 'chicken', 'price' : 23000}
f = {'store' : 'F', 'menu' : 'pork', 'price' : 30000}

Total = [a, b, c, d, e, f]

l = input('what food?:  ')
p = int(input('how much you want to spend?  '))

found = False
for i in range(5):
    if Total[i]['menu'] == l and int(Total[i]['price']) <= p:
        print('menu', Total[i]['store'], 'price', Total[i]['price'])
        found =  True

if not found:
    print ("No stores were found.")