A · SetupBeginner40 min read
2. Virtual environments & toolchain
Python · 52 pages source format
Never pollute global Python. venv per project. pip install inside venv. requirements.txt for reproducibility.
What you'll learn
- python -m venv
- activate/deactivate
- pip install
- requirements.txt
Create and activate venv
python -m venv .venv creates an isolated environment. Activate before every session.
python -m venv .venv
# macOS / Linux
source .venv/bin/activate
# Windows
.venv\Scripts\activate
python --version
pip --versionDo this now
Create .venv in py-journey. Activate. Run which python (or where python on Windows).
Clear?
Install packages
pip install httpx pytest. pip freeze > requirements.txt commits exact versions.
Do this now
pip install httpx pytest. pip freeze > requirements.txt. Commit both.
Clear?
Editor setup
VS Code / Cursor: select .venv interpreter. Python extension enables run/debug.
Do this now
Open py-journey in editor. Confirm interpreter points to .venv.
Pro tip. Forgot to activate? Symptoms: ModuleNotFoundError for packages you "installed".
Clear?