python classes defined dynamically with `type` disappear -

i'm using python's type dynamically declare classes. like:

class parentclass(object):     pass  class_name in ['a', 'b', 'c', 'd', 'e']:     type(class_name, (parentclass,), {})     print('subclasses of parentclass:', parentclass.__subclasses__()) 

usually, print line prints 1, 2, 3, 4, , 5 subclasses.

but sometimes, prints 1, 2, 3, 1, 2 subclasses: classes d , e. , parentclass.__subclasses__() anywhere else array [d, e].

and weirdest part changing other, unrelated code in other places in project affects it.

is possible that, because i'm not assigning classes name, they're being garbage collected? , that's why parentclass.__subclasses__() can't find class objects anymore?

is possible that, because i'm not assigning classes name, they're being garbage collected? , that's why parentclass.__subclasses__() can't find class objects anymore?

yes, it. see the documentation __subclasses__ method:

each new-style class keeps list of weak references immediate subclasses. method returns list of references still alive.