def draw_lines(self):
        """Draw lines which cross the screen."""

        for parent in self.parents:

            parent_center = parent.rect.center
            segment_color = parent.line_color

            for child in parent.children:

                try:
                    start, end = clip_segment(
                        parent_center,
                        child.rect.center,
                    )

                except ValueError:
                    pass

                else:

                    draw_line(
                        SCREEN,
                        segment_color,
                        start,
                        end,
                        4,
                    )
Draw lines which cross the screen.
nodezator/graphman/socketparenthood/draw/__init__.py