Use Pycache Prefix to Move pyc Files out of Your Source Code Starting in Python 3.8

One way to configure the pycache prefix is to set the PYTHONPYCACHEPREFIX environment variable.

As an example, I'll create an example project that looks like this:

.
├── bytecodes
└── codes
    ├── main.py
    └── my_module.py

As you might guess, I want my source code in codes and my bytecode in bytecodes. Also, main.py imports a function from my_module.py.

Now, in order to move the pyc files to the bytecodes directory, I'll set an environment variable, and run the program:

PYTHONPYCACHEPREFIX=$(pwd)/bytecodes python3 codes/main.py

Now, let's see what our file tree looks like:

.
├── bytecodes
|      |── Library
...
│      └── Users
│          └── tyler
│              └── tmp
│                  └── test_code
│                      └── codes
│                          └── my_module.cpython-38.pyc
└── codes
    ├── main.py
    └── my_module.py

As expected, Python has created a parallel file structure inside of the bytecodes directory where it stores the compiled bytecode.

Similar to the previous example, we can use the -X option and specify our path.

python3 -X pycache_prefix=bytecodes codes/main.py

This is equivalent to the example in step 1. All of the compiled bytecode is now located in our bytecodes directory.