Way to have compiled python files in a separate folder?

Update:

In Python 3.8 -X pycache_prefix=PATH command-line option enables writing .pyc files to a parallel tree rooted at the given directory instead of to the code tree. See $PYTHONPYCACHEPREFIX envvar^{credits: @RobertT’ answer}

The location of the cache is reported in sys.pycache_prefix (None indicates the default location in __pycache__ [since Python 3.2] subdirectories).

To turn off caching the compiled Python bytecode, -B may be set, then Python won’t try to write .pyc files on the import of source modules. See $PYTHONDONTWRITEBYTECODE envvar^{credits: @Maleev’s answer}

^{Old [Python 2] answer:}

There is PEP 304: Controlling Generation of Bytecode Files. Its status is Withdrawn and corresponding patch rejected. Therefore there might be no direct way to do it.

If you don’t need source code then you may just delete *.py files. *.pyc files can be used as is or packed in an egg.