💬 Question: What is the difference between Python’s is and == operators? Answer The Python “==” operator compares equality of values whereas the Python “is” operator compares identity of objects, i.e., do the two operands point to the same object in memory. For example, the expression [1, 2, 3] == [1, 2, 3] returns True … Read more
Understanding Python’s setattr() and getattr() Functions Next, you’ll learn about the “normal”, non-nested and non-recursive get and set attribute functions. If you already know them well, there’s no need to read this section and you can skip ahead right to the problem formulation and solution. Let’s start with the setattr() function, followed by getattr(). setattr() … Read more
This quick tutorial will show you how to return a value from a nested function. I assume you have your reasons for doing so. However, a word of warning: ⚡ Attention: The main reason you want to create “nested functions”, i.e., inner and outer functions in Python, is to use them for closures and decorators. … Read more
The “TypeError: ‘method’ object is not subscriptable” occurs when you call a method using square brackets, e.g., object.method[3]. To fix it, call the non-subscriptable method only with parentheses like so: object.method(3). How Does the Error Occur (Example) In the following minimal example, you attempt to define a custom “list” class and you try to access … Read more
This article will show you how to retrieve a single generator element in Python. Before moving forward, let’s review what a generator does. Quick Recap Generators 💡 Definition Generator: A generator is commonly used when processing vast amounts of data. This function uses minimal memory and produces results in less time than a standard function. … Read more
Python __version__ Attribute Python contains many “Magic Methods/Attributes”. One of these is __version__ commonly called “Dunder version” because of the double underscore before and after version. In this article, I will briefly look at what a Dunder Method/Attribute is and talk about __version__. What Does a Dunder Method/Attribute Do? Dunder Methods/Attributes, also called “Magic Methods” … Read more
Static class variables and methods in Python: How do I create static class variables or methods in Python? Are static class variables possible in Python? This article will give you a comprehensive answer to these questions! 🔍 Experiment: If we search “static class variables” in the Python documentation we will not find any close to … Read more
This tutorial is drawn from my book The Art of Clean Code (NoStarch 2022): Write Clean & Simple Code Story: I learned to focus on writing clean code the hard way. One of my research projects during my time as a doctoral researcher in distributed systems was to code a distributed graph processing system from … Read more
Overview: Mutable objects are Python objects that can be changed. Immutable objects are Python objects that cannot be changed. The difference originates from the fact the reflection of how various types of objects are actually represented in computer memory. Be aware of these differences to avoid surprising bugs in your programs. Introduction To be proficient … Read more
Ok, I must admit at the beginning that this topic is a bit of a clickbait – but if you find it cheating, I have to write in my defense that it was in good faith. If you were starting to write a book, it wouldn’t cross your mind to ask “what are the top … Read more
object.__aiter__(self) object.__anext__(self) 💡 Summary: Python’s __aiter__() and __anext__() methods are used to implement an asynchronous for loop (keywords: async for). In contrast to a normal (synchronous) for loop, an asynchronous for loop iterates over an asynchronous source. __aiter__() returns an asynchronous iterator object (in many cases it’s simply a reference to itself: return self) __anext__() … Read more
object.__aexit__(self, exc_type, exc_val, exc_tb) 💡 Summary: Python’s __aexit__() magic method is semantically similar to __exit__() but is used for asynchronous and parallel programming. Python calls the __aexit__() magic method when leaving an async with block whereas the __aenter__() method is called when entering it. An object that implements both __aenter__() and __aexit__() methods is called … Read more