Here, the condition of the while loop is alwaysTrue. However, if the user entersend, the loop termiantes because of thebreakstatement. Pythonwhileloop with anelseclause In Python, awhileloop can have an optionalelseclause - that is executed once the loop condition isFalse. For example, coun...
importselect# 创建一个select对象selector=select.select([sys.stdin],[],[])# 循环等待输入whileTrue:# 等待输入ready_to_read,_,_=selector.select()# 如果有数据可读ifready_to_read:# 读取输入command=raw_input().lower()# 处理输入ifcommand=="commands":print'"look around"'print'"explore"'print...
= 'q': # Give all the choices in a series of print statements. print("\n[1] Enter 1 to order Thai.") print("[2] Enter 2 to order Indian.") print("[3] Enter 3 to order Mexican.") print("[4] Enter 4 to order Chinese.") print("[q] Enter q to quit....
/usr/bin/python3 var = 1 while var == 1 : # This constructs an infinite loop num = int(input("Enter a number :")) print ("You entered: ", num) print ("Good bye!") 当执行上面的代码,它产生以下结果 - Enter a number :20 You entered: 20 Enter a number :29 You entered: 29 ...
如果你對for迴圈或if陳述句不熟悉,可以閱讀〈Python for 迴圈(loop)的基本認識與7種操作〉、〈Python if 陳述句的基礎與3種操作〉。 Python while 迴圈句基本認識 先來看一個簡單的while迴圈。 例子是這樣的,你要用Python印出1到100。你可以設定一個變數i,並在while後頭陳述符合需求的條件,條件是只要i小於...
Python3 循环语句 Python中的循环语句有 for 和 while。 Python循环语句的控制结构图如下所示: 一、while循环 Python 中 while语句 的一般形式: while 判断条件: 语句 1. 2. 注意冒号和缩进。另外,在Python中没有 do…while 循环。 实例(使用了 while 来计算 1 到 100 的总和) ...
The basic loop structure in Python is while loop. Here is the syntax.Syntax:while (expression) : statement_1 statement_2 ...The while loop runs as long as the expression (condition) evaluates to True and execute the program block. The condition is checked every time at the beginning of...
循环控制语句可以更改语句执行的顺序。Python支持以下循环控制语句: break结束全部循环,跳出整个循环 continue结束本次循环,进入下次循环 shell脚本里用break2可以跳出2层循环,但python不可以,这不是好语法,会造成语义混乱 回到顶部 2.while循环 参考文章: http://www.runoob.com/python/python-while-loop.html ...
本教程将教你如何在 Python 编程中使用while 循环以及何时使用它。 译自How (and When) to Use a Python While Loop,作者 Jack Wallen。 While 循环是编程的一个基本要素。While循环所做的是继续执行一条语句(或一组语句),直到满足特定条件。一个显而易见的例子(许多人都会理解)可能是这样的:只要我的银行账...
A while loop is a programming concept that, when it's implemented, executes a piece of code over and over again while a given condition still holds true. The above definition also highlights the three components that you need to construct the while loop in Python: The while keyword; A cond...