Apply a function elementwise, updating the HTML
        representation with a style which is selected in
        accordance with the return value of a function.

        .. versionadded:: 0.21.0

        Parameters
        ----------
        cond : callable
            ``cond`` should take a scalar and return a boolean
        value : str
            applied when ``cond`` returns true
        other : str
            applied when ``cond`` returns false
        subset : IndexSlice
            a valid indexer to limit ``data`` to *before* applying the
            function. Consider using a pandas.IndexSlice
        kwargs : dict
            pass along to ``cond``

        Returns
        -------
        self : Styler

        See Also
        --------
        Styler.applymap

def where(self, cond, value, other=None, subset=None, **kwargs):
        """
        Apply a function elementwise, updating the HTML
        representation with a style which is selected in
        accordance with the return value of a function.

        .. versionadded:: 0.21.0

        Parameters
        ----------
        cond : callable
            ``cond`` should take a scalar and return a boolean
        value : str
            applied when ``cond`` returns true
        other : str
            applied when ``cond`` returns false
        subset : IndexSlice
            a valid indexer to limit ``data`` to *before* applying the
            function. Consider using a pandas.IndexSlice
        kwargs : dict
            pass along to ``cond``

        Returns
        -------
        self : Styler

        See Also
        --------
        Styler.applymap
        """

        if other is None:
            other = ''

        return self.applymap(lambda val: value if cond(val) else other,
                             subset=subset, **kwargs)