python第六次練習

例題7-4

  描述：編寫一個在用戶輸入quit後結束的循環。
  代碼：

prompt = 'Please enter the pizza toppings '
prompt += '\n(Enter "quit" if you finish):'

while True:
    toppings = input(prompt)
    if toppings == 'quit':
        break
    print('We will add ' + toppings + ' to the pizza.')

  結果：

例題7-8

  描述：使用while實現列表轉移。
  代碼：

sandwich_orders = ['Mini Sandwich', 'Jagabe Sandwich', 'Tuna Sandwich']
finished_sandwiches = []
while sandwich_orders:
    sandwich = sandwich_orders.pop()
    print('I made your ' + sandwich + '.')
    finished_sandwiches.append(sandwich)
print('All sandwiches are finished: ')
for sandwich in finished_sandwiches:
    print(sandwich)

  結果：

例題7-9

  描述：使用while將一個列表中多個重複的指定元素刪除。
  代碼：

sandwich_orders = ['pastrami', 'jagabe', 'tuna', 'pastrami', 'pastrami']
print('Pastrami sandwiches are sold out!')

while 'pastrami' in sandwich_orders:
    sandwich_orders.remove('pastrami')
print(sandwich_orders)

  結果：

例題7-10

  描述：編寫一個程序，調查用戶夢想度假地，包括提示語句和結果。
  代碼：

responses = {}
polling_active = True
while polling_active:
    name = input('\nWhat is your name? ')
    prompt = 'If you could visit one place in the world, '
    prompt += 'where would you go?'
    response = input(prompt)
    responses[name] = response
    repeat = input('Would you like another person to respond? (yes/no)')
    if repeat == 'no':
        polling_active = False
print('\n--- Poll Results ---')
for name,response in responses.items():
    print(name + ' would go to ' + response + '.')

  結果：

發現的問題：

1. 一個句子太長可以用
   prompt =
   Prompt +=
   的方式
2. 如果程序陷入無限循環，可按Ctrl + C，也可關閉顯示程序輸出的終端窗口。
3. 不要忘記冒號
4. Input(prompt)
5. Remove刪掉第一個列表中的該元素
   While ‘alice’ in users:
   Users.remove(‘alice’)
6. 7-5 7-6 7-10
7. 使用active
8. sandwich_orders.remove()不要只寫remove()
9. 不要忘記.items()