screens.py 文件源码

def delete_lines(self, count=None):
        """Deletes the indicated # of lines, starting at line with
        cursor. As lines are deleted, lines displayed below cursor
        move up. Lines added to bottom of screen have spaces with same
        character attributes as last line moved up.

        :param int count: number of lines to delete.
        """
        count = count or 1
        top, bottom = self.margins

        # If cursor is outside scrolling margins it -- do nothin'.
        if top <= self.cursor.y <= bottom:
            #                v -- +1 to include the bottom margin.
            for _ in range(min(bottom - self.cursor.y + 1, count)):
                self.buffer.pop(self.cursor.y)
                self.buffer.insert(bottom, list(
                    repeat(self.cursor.attrs, self.columns)))

            self.carriage_return()