Getting Started

Install Python, set up virtualenv, and manage packages with pip.

Python is a runtime language that runs on the CPython VM (or alternatives like PyPy). It’s the go-to language for scripting, data science, machine learning, and web back-ends.

Setup

Install macOS:

brew install python

Install Ubuntu:

sudo apt-get install python3 python3-pip

Install Windows: Download from python.org and check “Add Python to PATH” during install.

Version Management

Use pyenv to manage multiple Python versions:

curl https://pyenv.run | bash
pyenv install 3.12.0
pyenv global 3.12.0

Virtual Environments

Always isolate project dependencies:

python -m venv .venv
source .venv/bin/activate   # macOS / Linux
.venv\Scripts\activate      # Windows

pip

pip is the package manager. Declare dependencies in requirements.txt:

flask==3.0.0
requests>=2.31

Install them:

pip install -r requirements.txt

Next: Basics