In many situations, you’ll need to find the number of items stored in a data structure. Python’s built-in function len() is the tool that will help you with this task. There are some cases in which the use of len() is straightforward. However, there are other times when you’ll need to understand how this function works in more detail and how to apply it to different data types. In this tutorial, you’ll learn how to: Find the length of built-in […]

If you’ve ever tried to parse an XML document in Python before, then you know how surprisingly difficult such a task can be. On the one hand, the Zen of Python promises only one obvious way to achieve your goal. At the same time, the standard library follows the batteries included motto by letting you choose from not one but several XML parsers. Luckily, the Python community solved this surplus problem by creating even more XML parsing libraries. Jokes aside, […]

If you’re using Python in the world of data science or scientific computing, you will soon discover that Python has two different packaging systems: pip and Conda. Which raises some questions: How are they different? What are the tradeoffs between the two? Which should you use? While it’s not possible to answer this question for every situation, in this article you will learn the basic differences, constrained to: Python only; Conda has support for other languages but I won’t go […]

With Python’s property(), you can create managed attributes in your classes. You can use managed attributes, also known as properties, when you need to modify their internal implementation without changing the public API of the class. Providing stable APIs can help you avoid breaking your users’ code when they rely on your classes and objects. Properties are arguably the most popular way to create managed attributes quickly and in the purest Pythonic style. In this tutorial, you’ll learn how to: […]

The fractions module in Python is arguably one of the most underused elements of the standard library. Even though it may not be well-known, it’s a useful tool to have under your belt because it can help address the shortcomings of floating-point arithmetic in binary. That’s essential if you plan to work with financial data or if you require infinite precision for your calculations. Towards the end of this tutorial, you’ll see a few hands-on examples where fractions are the […]

Python 3.10 is now available–but should you switch to it immediately? And if not now, when? The short answer is, no, you probably don’t want to switch immediately; quite possibly you can’t switch immediately. To understand why, we need to consider Python packaging, the software development process, and take a look at the history of past releases. We can then make a guess about when Python 3.10 will actually be usable. The problems with a new major Python release I’m […]

Python’s built-in function sum() is an efficient and Pythonic way to sum a list of numeric values. Adding several numbers together is a common intermediate step in many computations, so sum() is a pretty handy tool for a Python programmer. As an additional and interesting use case, you can concatenate lists and tuples using sum(), which can be convenient when you need to flatten a list of lists. In this tutorial, you’ll learn how to: Sum numeric values by hand […]