input: Write a python function to load a plugin class dynamically from a string.
  assert load_plugin_class('os.path') == os.path
  assert load_plugin_class('datetime.datetime') == datetime.datetime
  assert load_plugin_class('re.Pattern') == re.Pattern
output: def load_plugin_class(class_path):
      module_path, class_name = class_path.rsplit('.', 1)
      module = __import__(module_path, fromlist=[class_name])
      return getattr(module, class_name)