python循环for，range,xrange；while
>>>range(1,5)#代表从1到5(不包含5)[1,2,3,4]>>>range(1,5,2)#代表从1到5，间隔2(不包含5)[1,3]>>>range(5)#代表从0到5(不包含5)[0,1,2,3,4]array=[1,2,5,3,6,8,4]#其实这里的顺序标识是[1,2,5,3,6,...
