python1加到n

while True:
    a = 0
    n = input('從0開始加到您所輸入的數字：')
    if n.isdigit() == True:
        n = int(n)
        for i in range(n+1):
            a += i
        else:
            print('計算完成，結果為', a)
        s = input('輸入q退出或者任意字符繼續 : ')
        if s == 'q':
            break
    else:
        print('請輸入正整數！')
print('程序結束！')