2018.09.18 while循环

**  "loop" 循环   注意要有引号。

**pass 过

#打印 1-100

start = 1
while start < 101:
    print("loop",start)
    start += 1

#打印1-49，81-100. 60-80的平方

start = 1
while start <101 :
    if start >49 and start < 60:
        pass
    elif start >59 and start < 81:
        print("loop",start*start )
    else:
        print("loop",start)
    start += 1