import .. in python but 2.4 or before(2)

my implementation ended up with following code....

import os
import sys
import imp

def module(root_path, module_name, locals):
  # avoid reload, do not import twice.
  try:
    return sys.modules[module_name]
  except KeyError:
    pass

  if os.path.isabs(root_path):
    base_path = os.path.normpath(os.path.dirname(root_path))
  else:
    path = os.path.dirname(os.path.abspath(locals['__file__']))
    base_path = os.path.normpath(os.path.join(path, root_path))

  search_paths = [base_path]
  package_name  = ''
  for m in module_name.split('.'):
    mod = import_one(search_paths, m)
    if package_name:
      setattr(locals[package_name], m, mod)
      package_name = package_name + '.' + m
    else:
      package_name = m
    locals.update({package_name:mod})
    try:
      search_paths = mod.__path__
    except AttributeError:
      assert(package_name == module_name)
      break


def import_one(search_paths, module_name):
  try:
    f, pathname, description = imp.find_module(module_name, search_paths)
  except ImportError:
    raise ImportError('no such module %s in %s', module_name, search_paths)

  try:
    mod = imp.load_module(module_name, f, pathname, description)
  finally:
    if f:
      f.close()
    return mod