def set_diag_border(self, diag_border=1):
        self.diag_border = diag_border

    ###########################################################################
    #
    # Internal Format properties. These aren't documented since they are
    # either only used internally or else are unlikely to be set by the user.
    #
    ###########################################################################
Set the Format diag_border property.
dataset/ETHPy150Open jmcnamara/XlsxWriter/xlsxwriter/format.py/Format.set_diag_border