Python
Fixing “TypeError: object is not callable” in Python (Including list is not callable)
You put call brackets after something that is not a function. The type in the message names it. The usual cause is…
All guides
Every guide on the site, newest first. Explanations, projects and fixes written in plain English.
Python
Fixing “TypeError: object is not subscriptable” in Python
You used square brackets on something that does not support them: an int, a None, a function, a method you forgot to…
Machine Learning
Machine Learning with Python
A first machine learning model in scikit-learn, explained line by line: loading data, splitting it, training, evaluating, and why the train/test split…
JavaScript
JavaScript Basics
The syntax of JavaScript in one page: variables, types, operators, functions, conditions, loops, arrays, objects and the mistakes beginners make with each.
Python
pip Not Working After Upgrading to Python 3.14
Installed Python 3.14 and now pip is missing, points at the old version, or fails to install packages? The three causes, the…
JavaScript
Introduction to JavaScript
What JavaScript is, where it runs, what it is used for, and how it relates to HTML and CSS — plus your…
Programming Projects
Build a REST API With FastAPI
A complete, working REST API in FastAPI: models, CRUD routes, validation, a SQLite database, automatic docs and tests. About 120 lines, built…
Python
How to Import from the Parent Directory in Python
Four ways to import a module from a parent folder, why sys.path.append is the worst of them, and the editable install that…
Programming Basics
Functional Programming vs OOP
Objects bundle state with the code that changes it; functional programming keeps data and transformations apart and avoids changing anything. The same…
Python
How to Convert a Python Dictionary to YAML
Convert a dict to YAML with PyYAML, control the formatting, handle nested data and Unicode, and load YAML back safely.
Career & Learning
Self-Taught Programmer vs a Degree
What a computer science degree gives you that self-study does not, what it does not give you, and how the choice actually…
Keep going — pick your next guide
The fastest way to improve is to read one guide, then build the thing it describes. Start with the basics, or jump straight to a project.