ImportError: cannot import name 'Serial' from 'serial' (unknown location)

I encountered the same problem. I first uninstalled pyserial from all pip, pip3, and conda (I had it on all 3), and then re-installed it. It then worked fine for me. Hope that helps!

I got exactly this problem, as well. It was caused by the "pyserial" and "serial" libraries installed on per-user basis with pip while pyserial was also installed system-wide (possibly in a different version, using the Linux package manager).

Solution

Removing the per-user version fixed the problem in my case.