import os
# destination for screenshots
file_path = '/media/LITTLE_ONE/vsfx408/houdini/renders/parameter_test'
# root naming convention
screenshot_name = 'test'
start = 1
end = 240
while start < end:
hou.setFrame(start)
os.system( 'import -window root %s/%s.%03d.png' % (file_path, screenshot_name, start) )
start += 1