重载符模板代码：

class Vector:def __init__(self, a, b):self.a = aself.b = bdef __str__(self):return 'Vector (%d, %d)' % (self.a, self.b)def __add__(self, other):return Vector(self.a + other.a, self.b + other.b)
v1 = Vector(2, 10)
v2 = Vector(5, -2)
print(v1 + v2)

输出：

Vector (7, 8)