[DiapDealer]

On Windows, you should be able to run sigil-python3.exe with the -EO command-line switches. I won't guarantee it can be used externally from Sigil with no issues whatsoever, but it should be able to launch and load the bundled modules OK. The python plugin launcher files themselves, for instance, won't be included in sys.path, nor will the plugin's directory when running it in this manner.

The -E switch isn't entirely necessary (especially if you have no other version of Python installed on your system). It just tells python to ignore any Python environment variables. It helps ensure the isolation of Sigil's bundled pyrhon from any other python installations.

Full disclosure: on Windows, the Python interpreter is launched (when running plugins) with -EOBu as command-line parameters.

Not much to gain by using it in this manner, though. It's just a standard python.org 3.4.3 install with a few extra modules and a tweaked site.py.