[Tutor] Class

[Rex Florian]

Hello,

Below is a class I am using to comprehend how class works.  
The code came from tutorialspoint.com and executes correctly but I do not understand why it works.
The original example defined just v1 and v2.  I decided to experiment and instantiated v3.
The executed the print statement yields a correct answer which baffles me as to how.
I also tried (v1 + v2 + v3 + v1) which works as well.

Can someone explain how Python achieves the vector addition of more than 2 vectors
without some kind of looping?

class Vector:
   def __init__(self, a, b):
      self.a = a
      self.b = b

   def __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)
v3 = Vector(16,-14)
print(v1 + v2 + v3)