def METHOD_NAME(mathstr):
    """Parse a `str` as a function from the `operator` module
    Parameters
    ----------
    mathstr : `str`
        a `str` representing a mathematical operator
    Returns
    -------
    op : `func`
        a callable `operator` module function
    Raises
    ------
    KeyError
        if input `str` cannot be mapped to an `operator` function
    Examples
    --------
    >>> parse_operator('>')
    <built-in function gt>
    """
    try:
        return OPERATORS[mathstr]
    except KeyError as exc:
        exc.args = ('Unrecognised operator %r' % mathstr,)
        raise