code: def set_margins(self, left,top,right=-1):
          "Set left, top and right margins"
          self.l_margin=left
          self.t_margin=top
          if(right==-1):
              right=left
          self.r_margin=righf set_margins(self, left,top,right=-1):
          "Set left, top and right margins"
          self.l_margin=left
          self.t_margin=top
          if(right==-1):
              right=left
          self.r_margin=right
docs: Set left, top and right margins