Loading... # 第六章 输入与while循环 ## 6.1 函数input()的工作原理 函数`input()`让程序暂停运行,等待用户输入一些文本。获取用户输入后,Python将其存储在一个变量中。 ```python name = '' name = input("who are you?") print("Hello, " + name + "!") ``` > who are you? > 输入:tim > 输出: > Hello, tim! 函数input()接受一个参数:即要向用户展示的<font face = "楷体">提示或说明</font>。 程序等待用户输入,在用户按回车键后继续运行。 ### 6.1.1 用int()获取数值输入 使用函数input()时,Python会将用户输入解读为字符串。 可以使用`int()`函数,让Python将参数汇总的的字符串转化为数值。(与str()对应) ```python age = '' age = input("How old are you?\n") age = int(age) if age >= 18: print("You are an adult.") ``` > 输入:19 > 输出:You are an adult. ## 6.2 while循环 ```python num = 1 while num <= 5: print(num) num += 1 ``` > 1 > 2 > 3 > 4 > 5 ```python s = input("i am a repeater\n") while s != 'quit' print(s) s = input() ``` > 复读机,直到用户输入quit停止 ```python flag = True count = 5 while flag: print(count) count -= 1 if count < 0: flag = False ``` > 5 > 4 > 3 > 2 > 1 > 0 ### 6.2.1 在循环中使用break和continue ```python while True: s = input() if s == 'quit': break print("You just inputed " + s) ``` > 复读机,直到输入quit continue不多赘述,与C语言作用相同 ## 6.3 用while循环来处理列表和字典 ### 6.3.1 在列表之间移动元素 ```python target = ['apple', 'bannana', 'peach'] shopping_car = [] while target: cur = target.pop() print("Buy " + cur) shopping_car.append(cur) print("You have bought these:") print(shopping_car) print("These not bought:") print(target) ``` > Buy peach > Buy bannana > Buy apple > You have bought these: > ['peach', 'bannana', 'apple'] > These not bought: > [] ### 6.3.2 删除所有列表中的特定值 ```python fruits = ['apple', 'orange', 'peach', 'apple', 'apple'] while 'apple' in fruits: fruits.remove('apple') print(fruits) ``` > ['orange', 'peach'] ### 6.3.3 利用输入填充字典 ```python cilent = {} while True: name = input("Please input your name:") nick_name = input("Please input your nickname:") cilent[nick_name] = name re = input("Would you like to continue? (yes/no)") if re == 'no': break print(cilent) ``` 最后修改:2021 年 08 月 01 日 06 : 23 PM © 允许规范转载