It may very well be my own fiddling with PATH, but the script's standard #!/usr/bin/env python makes the Open With installation non-working. Changing the shebang to #!/usr/local/bin/python3 where it is located when installed with brew fixes the issue and Open With is working again.
Maybe it'll be useful for someone:
It may very well be my own fiddling with PATH, but the script's standard
#!/usr/bin/env python
makes the Open With installation non-working. Changing the shebang to#!/usr/local/bin/python3
where it is located when installed withbrew
fixes the issue and Open With is working again.macOS 10.15.6 Firefox 80.0.1 Open With 7.2.2