A Python iterable that returns one of two member variables.

gistfile1.py

class Vector():
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.index = 0
        
    def __iter__(self):
        return self
    
    def next(self):
        if self.index > 1:
            raise StopIteration
        
        self.index = self.index + 1
        if self.index == 1:
            return self.x
        else:
            return self.y

v = Vector(5, 6)

x, y = v

print "x: %d, y: %d" % (x, y)