163 posts tagged with "python"

The pyenv: python: command not found error occurs when pyenv is not properly configured to manage your Python versions. The solution is to ensure your shell's configuration files are correctly updated to point to pyenv's shims, which are small executable files that intercept commands like python and pip and redirect them to the correct Python version [4, 5].

You can switch Python versions with pyenv using three main commands: global, local, and shell. The method you choose depends on the scope you want for the new Python version.

Cloning a list in Python is essential to avoid unintended side effects, as simply assigning one list to another with the equals sign (=) creates a reference, not a new copy [1]. This means both variables point to the same list object in memory, and modifying one will modify the other. To properly clone a list, you need to understand the difference between a shallow copy and a deep copy.

Choosing the right Python environment and package management tool in 2025 depends on your project's complexity and your team's workflow. The tools available can be categorized into two main groups: those that manage Python versions (pyenv, asdf) and those that manage project dependencies (venv, virtualenv, Poetry). Combining these tools is often the most effective approach.

When you're diving into Python's Object-Oriented Programming (OOP) features, decorators like @property and @classmethod pop up all the time. They might seem similar at first glance, but they serve fundamentally different purposes. Getting them straight is key to writing clean, Pythonic code.

Let's cut through the noise and get straight to what they do and when you should use them.

As a Django app grows, managing database queries effectively is crucial for maintainability, performance, and testability. Storing them haphazardly is a recipe for disaster. The best place to store your queries is on custom Model Managers and QuerySets. This approach keeps your logic organized, reusable, and closely tied to the data it operates on. Here are the main variants for storing your queries, from the least recommended to the best practice.

Sometimes even the simplest programs deserve solid testing-especially when you're working in a team or trying to set strong standards for code quality. In this note, we'll take the most basic example-"Hello, World!"-and build out everything around it to demonstrate how doctests can be used effectively, even for something so trivial. The goal is to build intuition for testing, not just solve a toy problem.

Executing Doctests in Python: A Comprehensive Guide​

Doctest is a module in the Python Standard Library that enables you to write tests within the documentation of your code-typically inside docstrings. These tests look like interactive Python sessions (as if they were run in a Python shell), and the doctest module verifies that the output matches the expected result. While doctests are generally simpler than unit tests written with unittest or pytest, they are powerful for checking that code examples in documentation remain correct over time.

This guide explores the various ways to execute doctests in Python, from running them via the command line to embedding them in code and running them programmatically.

So I've been thinking lately about testing strategies again, and one question came up that I kept circling back to: does every function in my Python codebase need to have a doctest?

If you're writing doctests in Python using Gitpod or VS Code, you don't need much to get started. Python's built-in doctest module lets you write examples in your function's docstring using the familiar >>> prompt, and then run those examples as tests. This is great for small, focused functions or when you want your documentation to double as lightweight tests.