>>> import collections
  >>> import sys
  >>> class A:
  ...     def __init__(self, x, y):
  ...         self.x = x
  ...         self.y = y
  ... 
  >>> class B:
  ...     __slots__ = ('x', 'y')
  ...     def __init__(self, x, y):
  ...         self.x = x
  ...         self.y = y
  ... 
  >>> C = collections.namedtuple('C', ('x', 'y'))
  >>> a = A(1, 1)
  >>> b = B(1, 1)
  >>> c = C(1, 1)
  >>> d = {'x': 1, 'y': 1}
  >>> sys.getsizeof(a) + sys.getsizeof(a.__dict__) # Plain object
  344
  >>> sys.getsizeof(b) + sys.getsizeof(b.__slots__) # Plain object with slots
  120
  >>> sys.getsizeof(c) # Named Tuple
  64
  >>> sys.getsizeof(d) # Dict
  288

EDIT2: Included size of __slots__ tuple