Angle in float degrees of line of a linear gradient.

        Read/Write. May be |None|, indicating the angle should be inherited
        from the style hierarchy. An angle of 0.0 corresponds to
        a left-to-right gradient. Increasing angles represent
        counter-clockwise rotation of the line, for example 90.0 represents
        a bottom-to-top gradient. Raises |TypeError| when the fill type is
        not MSO_FILL_TYPE.GRADIENT. Raises |ValueError| for a non-linear
        gradient (e.g. a radial gradient).

def gradient_angle(self):
        """Angle in float degrees of line of a linear gradient.

        Read/Write. May be |None|, indicating the angle should be inherited
        from the style hierarchy. An angle of 0.0 corresponds to
        a left-to-right gradient. Increasing angles represent
        counter-clockwise rotation of the line, for example 90.0 represents
        a bottom-to-top gradient. Raises |TypeError| when the fill type is
        not MSO_FILL_TYPE.GRADIENT. Raises |ValueError| for a non-linear
        gradient (e.g. a radial gradient).
        """
        if self.type != MSO_FILL.GRADIENT:
            raise TypeError('Fill is not of type MSO_FILL_TYPE.GRADIENT')
        return self._fill.gradient_angle