timeline bookmarks
Houdini 20 has introduced the Bookmark class within the animation module. One of the cool utilizations of this feature is to provide a visual shot cut-range indicator for artists.
For more information, refer to the Houdini docs
Python
import os, hou
hou.hscript("123.cmd")
frame_start = int(os.environ['FS'])
frame_end = int(os.environ['FE'])
handle = int(os.environ['HANDLE'])
cut_range_bookmark = hou.anim.newBookmark("cut range", frame_start+handle, frame_end-handle)
cut_range_bookmark.setColor(hou.Color((0.3, 0.3, 0.3)))