while循环
while 条件:
代码块
条件为真时,执行代码块,如果不为真,就跳过while循环的代码块。
break:直接跳出当前的循环while。
while、else:当while不满足的时候会走else。当while不是正常退出(break就是非正常退出),不会走else,当while是正常退出的话,才会走else下面的模块。
1 age_of_oldboy = 56 2 count = 0 3 while count<3: 4 guess_age = int(input(">>>:")) 5 if age_of_oldboy == guess_age: 6 print("yes,you got it")
break 7 elif age_of_oldboy > guess_age: 8 print("think bigger!") 9 else: 10 print("think smaller!") 11 count+=1 12 else: 13 print("you try more")
while循环版本优化
1 for i in range(10): 2 print(i)
i:是临时变量
range:其实是一个迭代器,但是这里大家可以暂时理解为【0,1,2,3,4,5,6,7,8,9】,每循环一次,就是将数组里面的值赋值给i。
如果我们想隔一个值打印怎么办?判断是否可以被2整除吗?NO,太LOW
for i in range(0,10,2): print(i)
从0开始循环,2是步长,隔2个打印。
下面是优化代码:
1 age_of_oldboy = 56 2 count = 0 3 while count<3: 4 guess_age = int(input(">>>:")) 5 if age_of_oldboy == guess_age: 6 print("yes,you got it") 7 break 8 elif age_of_oldboy > guess_age: 9 print("think bigger!") 10 else: 11 print("think smaller!") 12 count+=1 13 if count==3: 14 guess_confirm = input("are you going on....") 15 if guess_confirm!='n': 16 count = 0 17 else: 18 print("you try more")
for , else 与while ,else 一样只有当程序正常退出的时候,我们才执行else里面的代码,但是当break非正常退出时,不会执行else下面代码的。
1 age_of_oldboy = 56 2 count = 0 3 for i in range(3): 4 guess_age = int(input(">>>:")) 5 if age_of_oldboy == guess_age: 6 print("yes,you got it") 7 break 8 elif age_of_oldboy > guess_age: 9 print("think bigger!") 10 else: 11 print("think smaller!") 12 else: 13 print("you try more")
continue:结束本次循环,直接跳到下次循环
break:结束当前循环
1 ''' 2 for i in range(10): 3 if i < 5: 4 print(i) 5 else: 6 continue 7 print("hehe") 8 9 ''' 10 for i in range(10): 11 print("-----------------",i) 12 for i in range(10): 13 print(i) 14 if i >5: 15 break