patch 8.0.0732: when updating a buffer modeless selection is lost commit https://github.com/vim/vim/commit/80dd3f9d41ce2ff6ab3544cdb266627bbdfc34a6 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Jul 19 12:51:52 2017 +0200 patch 8.0.0732: when updating a buffer modeless selection is lost Problem: When updating a buffer for a callback the modeless selection is lost. Solution: Do not insert or delete screen lines when redrawing for a callback and there is a modeless selection.

#!/usr/bin/python
#
# Program that writes a number to stdout repeatedly
#
# This requires Python 2.6 or later.

from __future__ import print_function
import sys
import time

if __name__ == "__main__":

    done = 0
    while done < 10:
        done = done + 1
        print(done)
        sys.stdout.flush()
        time.sleep(0.05)  # sleep 50 msec