code: def label_from_attrs(da, extra=''):
      ''' Makes informative labels if variable metadata (attrs) follows
          CF conventions. '''
  
      if da.attrs.get('long_name'):
          name = da.attrs['long_name']
      elif da.attrs.get('standard_name'):
          name = da.attrs['standard_name']
      elif da.name is not None:
          name = da.name
      else:
          name = ''
  
      if da.attrs.get('units'):
          units = ' [{}]'.format(da.attrs['units'])
      else:
          units = ''
  
      return '\n'.join(textwrap.wrap(name + extra + units, 30)f label_from_attrs(da, extra=''):
      ''' Makes informative labels if variable metadata (attrs) follows
          CF conventions. '''
  
      if da.attrs.get('long_name'):
          name = da.attrs['long_name']
      elif da.attrs.get('standard_name'):
          name = da.attrs['standard_name']
      elif da.name is not None:
          name = da.name
      else:
          name = ''
  
      if da.attrs.get('units'):
          units = ' [{}]'.format(da.attrs['units'])
      else:
          units = ''
  
      return '\n'.join(textwrap.wrap(name + extra + units, 30))
docs: Makes informative labels if variable metadata (attrs) follows
          CF conventions.