Python学习笔记6_用户输入和while循环

message = input("Tell me something, and I will repeat it back to you: ")
#程序等待用户输入，并在用户按回车键后继续运行
print(message)

name = input("Please enter your name: ")
print("Hello, " + name + "!")

prompt = "If you tell us who you are, we can personalize the messages you see."
prompt += "\nWhat is your first name? "
name = input(prompt)
print("\nHello, " + name + "!")

age = input("How old are you? ")
print(age)
# age = int(age)     必须转换类型
if age>18:
  print("Ture")

number = input("Enter a number, and I‘ll tell you if it‘s even or odd: ")
number = int(number)
if number % 2 == 0:
  print("\nThe number " + str(number) + " is even.")
else:
  print("\nThe number " + str(number) + " is odd.")

current_number = 1
while current_number <= 5:
  print(current_number)
  current_number += 1

prompt = "\nTell me something, and I will repeat it back to you:"
prompt += "\nEnter ‘quit‘ to end the program. "
message = ""                #创建了一个变量——message，用于存储用户输入的值。
                            #将变量message的初始值设置为空字符串""，让Python首次执行while代码行时有可供检查的东西
while message != ‘quit‘:
  message = input(prompt)
  print(message)

prompt = "\nTell me something, and I will repeat it back to you:"
prompt += "\nEnter ‘quit‘ to end the program. "
active = True
while active:
  message = input(prompt)
  if message == ‘quit‘:
    active = False
  else:
    print(message)

prompt = "\nPlease enter the name of a city you have visited:"
prompt += "\n(Enter ‘quit‘ when you are finished.) "
while True:
  city = input(prompt)
  if city == ‘quit‘:
    break
  else:
    print("I‘d love to go to " + city.title() + "!")

current_number = 0
while current_number < 10:
  current_number += 1
  if current_number % 2 == 0:
    continue           #等于结束后面语句
  print(current_number)

# 首先，创建一个待验证用户列表
# 和一个用于存储已验证用户的空列表
unconfirmed_users = [‘alice‘, ‘brian‘, ‘candace‘]
confirmed_users = []
# 验证每个用户，直到没有未验证用户为止
# 将每个经过验证的列表都移到已验证用户列表中
while unconfirmed_users:                             #循环将不断地运行，直到列表unconfirmed_users变空
  current_user = unconfirmed_users.pop()             #pop()以每次一个从列表末尾删除未验证的用户
                                                     #由于Candace位于列表末尾，因此其名字将首先 被删除、存储
                                                     #到变量current_user中并加入到列表confirmed_users中
  print("Verifying user: " + current_user.title())
  confirmed_users.append(current_user)
# 显示所有已验证的用户
print("\nThe following users have been confirmed:")
for confirmed_user in confirmed_users:
  print(confirmed_user.title())

pets = [‘dog‘, ‘cat‘, ‘dog‘, ‘goldfish‘, ‘cat‘, ‘rabbit‘, ‘cat‘]
print(pets)
#进入这个循环后，Python删除第一个‘cat‘并返回到while代码行
#然后发现‘cat‘还包含在列表中，因此再次进入循环。
while ‘cat‘ in pets:
  pets.remove(‘cat‘)
print(pets)

responses = {}                                 #定义一个空字典
# 设置一个标志，指出调查是否继续
polling_active = True
while polling_active:
  # 提示输入被调查者的名字和回答
  name = input("\nWhat is your name? ")
  response = input("Which mountain would you like to climb someday? ")
  # 将答卷存储在字典中
  responses[name] = response
  # 看看是否还有人要参与调查
  repeat = input("Would you like to let another person respond? (yes/ no) ")
  if repeat == ‘no‘:
    polling_active = False
# 调查结束，显示结果
print("\n--- Poll Results ---")
for name, response in responses.items():
  print(name + " would like to climb " + response + ".")