code: def load_file(self, path):
          
          data = yaml.load(open(path, 'r'))
          for key in self.property_keys:
              if key in data: setattr(self, key, data[key])
          self.parameters = self.parameter_list(data['parameters'])
docs: Load a YAML file with parameter data and other metadata.
  
          :param path: Path to YAML file.
          :type path: str
  
          The data in the YAML file is used to set the properties for the instance.
          The YAML file must contain a ``parameters`` key.
          It may optionally include any keys defined in :attr:`.property_keys`.
  
          .. code-block:: yaml
  
            # data.yml
            ---
            name: Shield frequencies
            parameters:
              - name: a
                value: 24.50
              - name: β
                value: 42.10
                meta:
                  phase_inverted: true
  
  
          .. code-block:: python
  
            parameters = Parameters('data.yml')
            parameters.name #=> 'Shield frequencies'
            parameters.get_value('a') #=> 24.50
            parameters.get_meta('β')['phase_inverted'] #=> true