def assign_value_if_none(value, default):
    """
    Assign a value to a variable if that variable has value ``None`` on input.

    Parameters
    ----------
    value : object
        A variable with either some assigned value, or ``None``

    default : object The value to assign to the variable ``value`` if
    ``value is None`` returns ``True``

    Returns
    -------
        new_value : object
            The new value of ``value``

    """
    return default if value is None else value