def source_getattr():
    """
    Creates a getter that will drop the current value
    and retrieve the source's attribute with the context key as name.
    """

    def source_getattr(_value, context, **_params):
        value = getattr(context["model"].source, context["key"])
        return _attr(value)

    return source_getattr
def source_getattr ( ) : def source_getattr ( _value , context , ** _params ) : value = getattr ( context [ "model" ] . source , context [ "key" ] ) return _attr ( value ) return source_getattr
Creates a getter that will drop the current value
    and retrieve the source's attribute with the context key as name.