python提供了for循环和while循环以及嵌套循环（在python中没有do..while循环）
while 循环语法：
while 判断条件： 执行语句......
实际案例：
numbers=[12,37,5,42,8,3]even=[];odd=[];while len(numbers)>0: number=numbers.pop(); if(number%2==0): even.append(number) else: odd.append(number);结果： numbers=[]; even=[8,42,12]; odd=[3,5,37]
循环使用else语句 实例：
count = 0while count < 5: print count, " is less than 5" count = count + 1else: print count, " is not less than 5“ 结果；
0 is less than 5 1 is less than 5 2 is less than 5 3 is less than 5 4 is less than 5 5 is not less than 5
做一些简单的小游戏练习
猜大小的游戏
import randoms = int(random.uniform(1,10))#print(s)m = int(input('输入整数:'))while m != s: if m > s: print('大了') m = int(input('输入整数:')) if m < s: print('小了') m = int(input('输入整数:')) if m == s: print('OK') break; 猜拳小游戏
import randomwhile 1: s = int(random.randint(1, 3)) if s == 1: ind = "石头" elif s == 2: ind = "剪子" elif s == 3: ind = "布" m = raw_input('输入 石头、剪子、布,输入"end"结束游戏:') blist = ['石头', "剪子", "布"] if (m not in blist) and (m != 'end'): print "输入错误，请重新输入！" elif (m not in blist) and (m == 'end'): print "\n游戏退出中..." break elif m == ind : print "电脑出了： " + ind + "，平局！" elif (m == '石头' and ind =='剪子') or (m == '剪子' and ind =='布') or (m == '布' and ind =='石头'): print "电脑出了： " + ind +"，你赢了！" elif (m == '石头' and ind =='布') or (m == '剪子' and ind =='石头') or (m == '布' and ind =='剪子'): print "电脑出了： " + ind +"，你输了！" 摇筛子游戏
import randomimport sysimport timeresult = []while True: result.append(int(random.uniform(1,7))) result.append(int(random.uniform(1,7))) result.append(int(random.uniform(1,7))) print result count = 0 index = 2 pointStr = "" while index >= 0: currPoint = result[index] count += currPoint index -= 1 pointStr += " " pointStr += str(currPoint) if count <= 11: sys.stdout.write(pointStr + " -> " + "小" + "\n") time.sleep( 1 ) # 睡眠一秒 else: sys.stdout.write(pointStr + " -> " + "大" + "\n") time.sleep( 1 ) # 睡眠一秒 result = []
python for 循环可以遍历任何序列的项目，如一个列表或者一个字符串。
for循环的语法：
for iterating_var in sequence statements(s)
简单案例
for letter in 'Python': # 第一个实例 print '当前字母 :', letter fruits = ['banana', 'apple', 'mango']for fruit in fruits: # 第二个实例 print '当前水果 :', fruit
通过序列索引迭代：将列表编程序列索引
fruits=["banana","apple","mango"]for index in range(len(fruits)): print(index) print("当前水果:"+fruits[index]) 循环使用else语句
在python中，for...else 表示这样的意思，for中的语句和普通的没有区别，else中的语句会在循环正常执行完（即for不是通过break跳出而中断的） 的情况下执行，while...else也是一样
for num in range(10,20): for i in range(2,num): if(num%i)==0: j=num/i print("%d 等于 %d * %d" %(num,i,j)) break else: print(str(num) +“是一个质数”) 使用内置enumerate 函数进行遍历 案例：
sequence=[12,34,34,23,45,76,89]for i ,j in enumerate(sequence): print(i,j)