class My(object):
        info = 0
m1 = My()
m2 = My()
m1.info = 13
m2.info = 5
print m1.info

class test(object):
	info = {}
	
t1 = test()
t2 = test()
t1.info['a'] = 1
print t1.info
print t2.info

>>> class test():
	def __init__(self):
		self.info = {}
		
>>> t1 = test()
>>> t2 = test()
>>> t1.info['a'] = 1
>>> print t1.info
{'a': 1}
>>> print t2.info
{}
>>> 

>>> class A():
...   a = {'a':1}
...
>>> foo = A()
>>> A.a
{'a': 1}
>>> foo.a
{'a': 1}
>>> foo1 = A()
>>> foo.a = {'b':2}
>>> foo1.a = {'c':3}
>>> A.a
{'a': 1}
>>> foo.a
{'b': 2}
>>> foo1.a
{'c': 3}
>>> foo.__class__.a
{'a': 1}

>>> class A(): a={'b':1}
>>> foo=A()
>>> foo1=A()
>>> foo.a['b']=100 # мы НЕ присваиваем атрибуту значение! foo.a = {'b':100} - присвоит.
>>> foo.a
{'b': 100}
>>> foo1.a
{'b': 100}