我们介绍了Python中迭代的基础:while循环、for循环、嵌套循环及其固有的操作符break and continue。
while 语句时还有另外两个重要的命令 continue,break 来跳过循环,continue 用于跳过该次循环,break 则是用于退出循环,此外"判断条件"还可以是个常值,表示循环必定成立,具体用法如下: i = 1whilei < 10: i+= 1ifi%2 > 0:#非双数时跳过输出continueprinti#输出双数2、4、6、8、10i= 1while1:#循环条件为...
在while 和 for 的循环体中,都可以使用 break 关键字终止整个循环体的运行。尤其是在和 if 的搭配使用中,当满足某个条件时,就终止整个循环结构。 whileTrue: username =input("输入用户名") paword =input("输入密码")ifusername =='admin'andpaword =='123456':print('login')break continue continue 则...
while expression: statement1 1. 2. 当expression 条件满足时,执行 statement1 语句, 语句执行完后,会返回第一行继续判断条件是否满足。如果该条件一直保持满足状态,循环语句无法退出,就会出现死循环的状态。 while True: print("hello, you") 1. 2. 为了让程序运行到一定阶段退出循环体,需要改变条件,当条件改...
1: statement_block_1 elif condition_2: statement_block_2 else: statement_block_3 ...
In Python, we can loop over list elements with for and while statements, and list comprehensions. Python list loop with for Python for statement iterates over the elements of a list in the order that they appear in the list. list_loop_for.py ...
初学 Python 时常见的 Python 错误是：没有使用正确的缩进，忘记某些代码行末尾的冒号，在为变量赋值之前使用变量，尝试更改不可变对象等。Python 需要正确的缩进在 Python 中，正确的缩进是必须的，Python 代码通过缩进来定义程序结构。Python 程序中不正确的缩进导致语法错误。如果从其他编程语言转到 Python，你可能不...
(Python 2 only) >> -Raise– A raise statement >> -Return– A return statement >> -Try– A try statement >> -While– A while statement >> -With– A with statement > -Expr– An expression >> -Attribute– An attribute, obj.attr >> -Call– A function call, f(arg) >> -IfExp...
In Python, you can specify an else statement to a for loop or a while loop. The else block is executed if a break statement is not used.
For loop– For loops are used to sequentially iterate over a python sequence. When the sequence has been iterated completely, the for loop ends and thus executes the next piece of code. The While Loop In Python The while loop statement is used to repeat a block of code till a condition ...