(val)
Return a textual representation of variable's value `val`. Argument
        `val` must be a float (for primitive variables) or an arbitrary
        Python object (for non-primitives).

        Derived classes must overload the function.
Return a textual representation of variable's value `val`. Argument
        `val` must be a float (for primitive variables) or an arbitrary
        Python object (for non-primitives).
Return a textual representation of variable s value val . Argument val must be a float ( for primitive variables ) or an arbitrary Python object ( for non - primitives ) .
def repr_val(val):
        """
        Return a textual representation of variable's value `val`. Argument
        `val` must be a float (for primitive variables) or an arbitrary
        Python object (for non-primitives).

        Derived classes must overload the function.
        """
        raise RuntimeError("variable descriptors must overload repr_val()")
def repr_val ( val ) : raise RuntimeError ( "variable descriptors must overload repr_val()" )