On Ubuntu install, as showing bellow, but: is it this ply here? the Readme say "it is not distributed or installed by package manager".
pip install ply
Collecting ply
Downloading ply-3.11-py2.py3-none-any.whl (49 kB)
|████████████████████████████████| 49 kB 5.0 MB/s
Installing collected packages: ply
Successfully installed ply-3.11
PS: say ply-3.11 but no releases here, https://github.com/dabeaz/ply/releases