这个用Python应该怎么写？

def my_sum(n):
    sum = 0
    for i in range(1, n+1, 2):
        if((i+1) % 4):
            sum += i
        else:
            sum -= i
    return sum


print(my_sum(int(input())))

n=int(input())
sum=0
flag=1
for i in range(n):
    sum+=(i*2+1)*flag
    flag=-flag
print(sum)