l.

            If a callable should take a 1d or 2d array and return a scalar.

            .. versionchanged:: 1.4.0

        vmin : float, optional
            Minimum bar value, defining the left hand limit
            of the bar drawing range, lower values are clipped to `vmin`.
            When None (default): the minimum value of the data will be used.
        vmax : float, optional
            Maximum bar value, defining the right hand limit
            of the bar drawing range, higher values are clipped to `vmax`.
            When None (default): the maximum value of the data will be used.
        props : str, optional
            The base CSS of the cell that is extended to add the bar chart. Defaults to
            `"width: 10em;"`.

            .. versionadded:: 1.4.0

        Returns
        -------
        Styler

        Notes
        -----
        This section of the user guide:
        `Table Visualization <../../user_guide/style.ipynb>`_ gives
        a number of examples for different settings and color coordination.

        Examples
        --------
        >>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
        >>> df.style.bar(subset=['A'], color='gray')  # doctest: +SKIP
        Nz