data science / python
Python for Data Science, Free
Python is the lingua franca of data science — and every library you need is free and open source. Learn the language, then the data stack: pandas, NumPy, and scikit-learn. All resources free and current.
If you're getting into data science, Python is where to start — it's readable, ubiquitous, and backed by the best data ecosystem anywhere. Learn the language fundamentals first (or brush up), then move to the "PyData" stack: pandas for wrangling data, NumPy for numerical work, and scikit-learn for machine learning. These are the official docs and the best free hands-on courses.
01 · THE LANGUAGE
Learn Python
Start with the language itself — free and beginner-friendly.
- The Python Tutorial (official) ↗Python's own guided tour of the language — authoritative, complete, and free. The canonical starting point.docs.python.org
- Kaggle Learn: Python ↗A fast, free, hands-on micro-course that gets you writing Python for data work in an afternoon, with a completion certificate.kaggle.com
02 · THE DATA STACK
pandas & scikit-learn
The libraries that make Python a data-science powerhouse.
- pandas Documentation (official) ↗The library for loading, cleaning, and reshaping tabular data — the workhorse of every data-science project. Includes a great "10 minutes to pandas" intro.pandas.pydata.org
- scikit-learn (official) ↗The standard machine-learning library for Python — with famously excellent free docs, user guides, and worked examples.scikit-learn.org