An inheritable lazy class with argument attachment.

lazy_class.py

def import_class(import_string, *a, **k):
  module, klass = import_string.rsplit('.', 1)

  def combine_args_kwargs(args, kwargs):
    new_args = a + args
    new_kwargs = k.copy()
    new_kwargs.update(kwargs)
    return new_args, new_kwargs

  def load_class():
    return getattr(__import__(module, fromlist=[klass]), klass)

  class lazy_class(object):
    def __new__(cls, *args, **kwargs):
      args, kwargs = combine_args_kwargs(args, kwargs)
      klass_obj = cls.as_class()
      return klass_obj(*args, **kwargs)

    class __metaclass__(type):
      def __new__(cls, *args, **kwargs):
        klass_obj = getattr(__import__(module, fromlist=[klass]), klass)

        def __init__(self, *args, **kwargs):
          args, kwargs = combine_args_kwargs(args, kwargs)
          klass_obj.__init__(self, *args, **kwargs)
        return type(import_string, (klass_obj,), {'__init__': __init__})

  return lazy_class