Encrypt Python source files and decrypt them on the fly during runtime.

Using pip:

pip install sourceprotected

sourceprotected path/to/src(.py)
Using key: fHC79...
Using encryption time: 1694...

With sourceprotected installed in your current environment, you can run/import encrypted files/modules as long as the SOURCEPROTECTED_KEY environment variable is set:

encrypted.py:

# -*- coding: sourceprotected -*-

-----BEGIN SOURCEPROTECTED FILE-----
gAAAAABk-eJaJarzMWy70GTRkRi6kjaD-zJy
-fHX_0G5VHTZjEKxJUvFhVWfWpX_j3LydmJo
pn7YrAj5CSqqPWgxUY_dSk5ELA==
-----END SOURCEPROTECTED FILE-----

main.py:

import encrypted  # Will decrypt encrypted.py on the fly.

Finally:

SOURCEPROTECTED_KEY=Bk92p... python -B main.py

sourceprotected uses a custom codec that will decrypt the file content using the SOURCEPROTECTED_KEY environment variable.

This codec is registered on startup by using a .pth file.

Credits goes to https://github.com/asottile-archive/future-fstrings for the implementation idea.