for循环100以内奇数累加：

sum = 0
for x in range(100):
    if (x % 2) == 1:
        sum = sum + x
print(sum)

for循环实现作业：

for x in L:
    print('hello,',x)

while循环实现作业：

n = 0
while n <= 2:
    print('hello, %s' % L[n])
    n = n + 1