code: def update_from_env_namespace(self, namespace):
          
          self.update(ConfigLoader(os.environ).namespace(namespace))
docs: Update dict from any environment variables that have a given prefix.
  
          The common prefix is removed when converting the variable names to
          dictionary keys. For example, if the following environment variables
          were set::
  
              MY_APP_SETTING1=foo
              MY_APP_SETTING2=bar
  
          Then calling ``.update_from_env_namespace('MY_APP')`` would be
          equivalent to calling
          ``.update({'SETTING1': 'foo', 'SETTING2': 'bar'})``.
  
          :arg namespace: Common environment variable prefix.
          :type env_var: :py:class:`str`