print('加', 2 + 3)
print('减', 1 - 3)
print('两个减号', 1 - -2)
print('乘', 2 * 4)
print('除', 9 / 3)
print('取整', 10 3, 10 4)
print('取整1', 10 / 3, 10 / 4)
print('模运算, 取余数', 10 % 3)  

print(round(1.2), round(1.5), round(2.5))

s, d, q, z = 1, 2, 3, 1

print('s == d', s == d)
print('s != d', s != d)
print('s > d', s > d)
print('d < z', d < z)

print('s == z', s == z)   #比较值
print('s is z', s is z)   #比较地址