function-call.py

def __call__(self, *args, **kwargs):
  """Overriding the __call__ function which makes the
  instance callable.
  """
  
  # fetching the function to be invoked from the virtual namespace
  # through the arguments.
  fn = Namespace.get_instance().get(self.fn, *args)
  
  if not fn:
    raise Exception("no matching function found.")
  
  # invoking the wrapped function and returning the value.
  return fn(*args, **kwargs)