Python ≥ 3.8 can put all Python .pyc cache files under one system-wide directory by the PYTHONPYCACHEPREFIX environment variable.

• Windows: set environment variable PYTHONPYCACHEPREFIX to %TEMP%
• Linux: in ~/.profile add export PYTHONPYCACHEPREFIX=${TMPDIR}
• macOS: in ~/.zshrc add export PYTHONPYCACHEPREFIX=${TMPDIR}

Pycache .pyc files can be set to NOT write anywhere with the PYTHONDONTWRITEBYTECODE environment variable.

• Windows: set environment variable PYTHONDONTWRITEBYTECODE to 1
• Linux: in ~/.profile add export PYTHONDONTWRITEBYTECODE=1
• macOS: in ~/.zshrc add export PYTHONDONTWRITEBYTECODE=1