def _convert_asset_timestamp_fields(dict_):
 for key in (_asset_timestamp_fields & viewkeys(dict_)):
  value = pd.Timestamp(dict_[key], tz='UTC')
  dict_[key] = (None if isnull(value) else value)
 return dict_

def _convert_asset_timestamp_fields ( dict_ ) : for key in ( _asset_timestamp_fields & viewkeys ( dict_ ) ) : value = pd . Timestamp ( dict_ [ key ] , tz = 'UTC' ) dict_ [ key ] = ( None if isnull ( value ) else value ) return dict_
takes in a dict of asset init args and converts dates to pd .