【python学习入门_day1】

python 入门

第一个程序：求100之内的偶数和

n = 100
s = 0
i = 0
while i<n:
    if (i%2) == 0:
        print(i)
        s += i
    i  = i + 1
print(s)

第二个程序：求1-2+3-4+5......-100结果

s = 0
i = 0
while i<=100:
    if i%2 != 0:
        s += i
    else:
        s -= i
    i = i+1
print(s)