Python’s built-in setattr(object, string, value) function takes three arguments: an object, a string, and an arbitrary value. It sets the attribute given by the string on the object to the specified value. After calling the function, there’s a new or updated attribute at the given instance, named and valued as provided in the arguments. For … Read more
Python’s built-in delattr() function takes an object and an attribute name as arguments and removes the attribute from the object. The call delattr(object, ‘attribute’) is semantically identical to del object.attribute. This article shows you how to use Python’s built-in delattr() function. Usage Learn by example! Here’s an example on how to use the delattr() built-in … Read more
If you’re like me, you love those TLDR; overviews to grasp the big picture quickly. Here is mine about Python’s compile() function: Python’s built-in compile() method returns an executable code object as an “Abstract Syntax Tree” represented as an ast object. By passing this code object into the exec() or eval() functions, you can run … Read more
This tutorial shows you how to use Python’s built-in eval() function. Why Using It? The main application of eval() is to take user input at runtime and run it as a Python expression. This way, you can create a calculator or allow users to perform custom computations on a computing cluster. However, this use also … Read more
The bubble sort does exactly what you’d expect it to do. It sorts an input list by treating each element as a bubble that climbs up the list. Each bubble rises as long as it is greater than the list elements. If a list element is smaller or equal to a list element, the bubble … Read more
The reference count is the number of times an object is referenced by a variable. If an object isn’t referenced anymore, it can be safely removed from the memory—what’s the use of an object nobody cares for anyway? This article shows you how to count the number of references to a Python object. What’s the … Read more
Python OS modules allow users to interact with files and directories. There are many functions or methods that Python employs in working with files or directories. However, in this article, we will consider three (3) essential functions. Now, let’s dive straight into it! Python – os.rename() Python OS rename() file method renames a file or … Read more
This tutorial shows you the meaning of captive user interfaces and why they’re discouraged under the Unix philosophy. I’ve written this as a first chapter draft for my upcoming book “From One to Zero” to appear in 2020 with San Francisco-based publisher NoStarch. What’s a Captive User Interface (CUI)? A captive user interface is a … Read more
Python’s exec() function executes the Python code you pass as a string or executable object argument. This is called dynamic execution because, in contrast to normal static Python code, you can generate code and execute it at runtime. This way, you can run programmatically-created Python code. Have you ever wondered about the limits of a … Read more
The Python complex() method returns a complex number object. You can either pass a string argument to convert the string to a complex number, or you provide the real and imaginary parts to create a new complex number from those. This article shows you how to use Python’s built-in complex() constructor. You’ll not only learn … Read more
This tutorial introduces the concept of default arguments in Python. A default argument is a function argument that takes on a default value if you don’t pass an explicit value for when calling the function. For example, the function definition def f(x=0): <body> allows you to call it with or without the optional argument x—valid … Read more
Static methods are special cases of class methods. They’re bound to a class rather than an instance, so they’re independent on any instance’s state. Python’s built-in function staticmethod() prefixes a method definition as an annotation @staticmethod. This annotation transforms a normal instance method into a static method. The difference between static (class) methods and instance … Read more