Returns or sets (if a value is provided) the chart's horizontal
        padding. This determines how much space will be on either side of the
        display area, as a proportion of overall width, and should be a value
        between 0 and 0.5

        :param float padding: If given, the chart's horizontal_padding\
        will be set to this.
        :raises ValueError: if a value outside of 0 < n < 0.5 is given.
        :rtype: float

def horizontal_padding(self, padding=None):
        """Returns or sets (if a value is provided) the chart's horizontal
        padding. This determines how much space will be on either side of the
        display area, as a proportion of overall width, and should be a value
        between 0 and 0.5

        :param float padding: If given, the chart's horizontal_padding\
        will be set to this.
        :raises ValueError: if a value outside of 0 < n < 0.5 is given.
        :rtype: float"""

        if padding is None:
            return self._horizontal_padding
        else:
            if not isinstance(padding, float):
                raise TypeError("padding must be float, not '%s'" % str(padding))
            if not 0 < padding < 0.5:
                raise ValueError(
                 "padding must be between 0 and 0.5 (not inclusive), not '%s'" % str(padding)
                )
            self._horizontal_padding = padding