Implementation of Singleton design pattern in Python (inspired from Alex Martelli talk)

singleton.py

# python -m doctest singleton.py
class Singleton(object):
	"""
	>>> s = Singleton()
	>>> s #doctest: +ELLIPSIS
	<hidden.Singleton object at 0x...>
	>>> p = Singleton()
	>>> p == s
	True
	"""
	def __new__(cls, *a, **k):
		if not hasattr(cls, '_inst'):
			cls._inst = super(Singleton, cls).__new__(cls, *a, **k)

		return cls._inst