The spacing between baselines of successive lines in this paragraph.
        A float value indicates a number of lines. A |Length| value indicates
        a fixed spacing. Value is contained in `./a:lnSpc/a:spcPts/@val` or
        `./a:lnSpc/a:spcPct/@val`. Value is |None| if no element is present.

def line_spacing(self):
        """
        The spacing between baselines of successive lines in this paragraph.
        A float value indicates a number of lines. A |Length| value indicates
        a fixed spacing. Value is contained in `./a:lnSpc/a:spcPts/@val` or
        `./a:lnSpc/a:spcPct/@val`. Value is |None| if no element is present.
        """
        lnSpc = self.lnSpc
        if lnSpc is None:
            return None
        if lnSpc.spcPts is not None:
            return lnSpc.spcPts.val
        return lnSpc.spcPct.val