Update to VPython 7.1.3. Thanks to Matt Craig for building the installers.
You can get the latest version this way: pip install vpython --upgrade
Or if using Anaconda, conda update -c vpython vpython
The wtext object lets you place in the middle of a canvas title or caption a dynamically modifiable piece of text. In the following example, as you drag the slider the wtext object to the right of the slider shows the current slider value:
from vpython import *
scene.width = scene.height = 200
box()
def f(s):
wt.text = '{} meters'.format(s.value)
scene.caption = 'Start of the caption.\n\n'
slider(bind=f, length=100, right=15) # right margin = 15 pixels
wt = wtext(text='0 meters')
scene.append_to_caption('\n\nBelow the slider.')
VPython 7.1.3 also fixes the attach_arrow mechannism, which was completely broken.
Bruce