#dop.py
class Dop1(object):
   def __init__(self, *args):
        do_something()
   def method_one():
        pass
   def method_two():
       pass
  ....
class Dop2(object):
   def __init__(self, *args):
        do_something()
   def method_one():
        pass
   def method_two():
       pass
...
#...etc
#main.py
from .dop import (Dop1, Dop2, ...)
DEFAULT_CONFIG = {"param1": "val1", "param2": "val2"}
class Main(object):
   def __init__(self, config):
        self.config = DEFAULT_CONFIG.copy()
        self.config.update(config)
        self.session = Session.create(self.config)
        self.dop1 = Dop1(self.session.id, self.config)
        self.dop2 = Dop2(self.session.id, self.config)
   def method():
        pass
  .....
   def destroy():
       self.session.close()
-------------------------
#usage.py 
from main import Main
starter1 = Main(configdict1)
starter2 = Main(configdict2)
....

class Base(object):
    param1 = None
    param2 = None
    param3 = None
class Child1(Base):
    pass
class Child2(Base):
    pass
if __name__ == "__main__":
    Base.param1 = 1
    Base.param2 = 2
    Base.param3 = 3
    ch1 = Child1()
    print ch1.param1, ch1.param2, ch1.param3
    ch2 = Child2()
    print ch2.param1, ch2.param2, ch2.param3

class Params:
    param1 = None
    param2 = None
    param3 = None
if __name__ == "__main__":
    Params.param1 = 1
    Params.param2 = 2
    Params.param3 = 3
    print Params.param1, Params.param2, Params.param3