Python
Python Best Practices
Naming, structure, error handling, virtual environments, type hints and testing — the habits that make Python code easy to come back to.
All guides
Every guide on the site, newest first. Explanations, projects and fixes written in plain English.
JavaScript
JavaScript Not Running From Your HTML File
The script tag is there and nothing happens, or the console is empty. Script placement, defer, wrong paths, cached files and browser…
C#
C# Deployment
How to publish a .NET application: framework-dependent versus self-contained builds, single-file output, trimming, Docker and configuration for production.
Python
Object-Oriented Programming (OOP) in Python
Classes, objects, inheritance and the dunder methods that make Python objects feel built in — plus dataclasses and when a function is…
PHP
PHP PDO Explained With Examples
PDO is the standard way to talk to a database from PHP. Connecting, prepared statements that stop SQL injection, fetching rows, transactions…
PHP
Introduction to PHP
What PHP is, how it differs from JavaScript, how a request becomes a page, and your first working script — with the…
PHP
PHP 7 vs PHP 8: What Changed and Whether to Upgrade
PHP 7 has been end-of-life since 2022. What PHP 8 changed in the language, what breaks when you move, why the upgrade…
Python
How to Fix ModuleNotFoundError: No Module Named ‘IPython’
IPython is missing from the interpreter you are running. Here is the fix, including the capitalisation trap and the Jupyter kernel mismatch…
Java
Java Not Working in VS Code
No IntelliSense, "cannot find symbol" on everything, or the run button does nothing? VS Code needs a JDK it can find and…
Programming Basics
Generics in Programming
What generics are, the problem they solve, and how they look in Java, C#, TypeScript and Python — with constraints, wildcards and…
Python
Python is vs ==: When to Use Which
== asks whether two values are equal; is asks whether they are the same object. Use is only for None, True, False…
Programming Basics
Concurrency and Multithreading
The difference between concurrency and parallelism, when threads help and when they do not, and the two bugs — race conditions and…
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