💬 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
Problem Formulation 💬 Question: How do you write a function that returns a real Python error instead of an “error code” such as -1 or None in case something got wrong? For example, you may want to check the function input arguments for having the correct type or length (in the case of iterable arguments) … Read more
💬 Question: What is the difference between return and break? When to use which? Let’s first look at a short answer before we dive into a simple example to understand the differences and similarities between return and break. Comparison Both return and break are keywords in Python. The keyword return ends a function and passes … Read more
Method 1: Return a New Empty List Using Square Brackets You can return an empty new list from a Python function using the square bracket notation [] after the return keyword using the expression return []. Here’s an example: The example also shows that the two created empty lists using two function calls point to … Read more
The Python return keyword allows you to define the return value of a function (e.g., return X). If you don’t explicitly set a return value or you omit the return statement, Python will implicitly return the following default value: None. There are three cases of what a function can return: Case 1: The function has … Read more
(Reading time: 19 minutes) The purpose of this article is to help you refresh your knowledge of all the basic Python keywords, data structures, and fundamentals. I wrote it for the intermediate Python programmer who wants to reach the next level of programming expertise. The way of achieving an expert level is through studying the … Read more
Problem Formulation and Solution Overview This article will show you how to delete variables and objects from memory using the del or None keywords. The Python language has several built-in reserved words having specific meanings called keywords. These keywords are reserved for Python and can not be used anywhere else. For example, declaring a variable, … Read more
💡 Question: Does Python have a for each or foreach loop? If so, how does it work? If not, what is the alternative? This article will shed light on these questions. I’ll give you the summary first and dive into the details later: Python has three alternatives to the “for each” loop: A simple for … Read more
Python’s magic method __del__() is called the finalizer method or, wrongly, the destructor method — the latter being wrong because it doesn’t actually destroy the object. Python calls __del__() upon deletion of a given instance. For example, the expression del my_obj will eventually initiate my_obj.__del__(). We call this a “Dunder Method” for “Double Underscore Method” … Read more
To customize the behavior of the non-equality operator x != y, override the __ne__() dunder method in your class definition. Python internally calls x.__ne__(y) to compare two objects using x != y. If the __ne__() method is not defined, Python will use the is not operator per default that checks for two arbitrary objects whether … Read more
The pass statement does nothing when executed. You can use it as a placeholder for future code so that you can focus on the high-level structure first and implement the details later. For example, functions, loops, class definitions, or if statements require at least one statement in their indentation block. Think of the pass statement … Read more