The backslash escape character ‘\’ is a special Python string character that is usually followed by an alphabetic character. For example, the tabular whitespace ‘\t’ and newline ‘\n’. In regular expressions, you can use the single escape to remove the special meaning of regex symbols. For example, to match the dot or asterisk characters ‘.’ … Read more
[toc] Overview Objective: The purpose of this article is to discuss and fix TypeError: ‘module’ object is not callable in Python. We will use numerous illustrations and methods to solve the issue in a simplified way. Example 1: Output: Now, the above output leads us to a few questions. Let us have a look at … Read more
Problem Formulation Say, you’ve written a number of unit tests using the unittest module in Pyhton. How can you disable specific unit tests temporarily? In other words: How to skip a unit test in Python’s unittest module? Example: Given the following three unit tests. How to disable tests 1 and 2? Method 1: Skip Test … Read more
[toc] Problem: There are two similarly-named functions in Python, exit() and sys.exit(). What’s the difference between them, and when should I use one over the other? Introduction In contrast to programming languages like C, there is no main() method in Python. Thus, when we run a program in Python, we essentially execute all the code in the top-level … Read more
Problem Formulation Given a string s. How to get a Boolean value that indicates whether all characters in the string are lowercase? Example: Say, you ask the user for input and you want to check whether all input characters are lowercase for further processing: If the user types in ‘alice’, the function should return True … Read more
This article will walk you through the different numerical systems that can be used to represent numbers in Python. The system that we usually use in our daily life is the decimal system and, as the name suggests, it is based on 10 basic digits from which we can obtain all the numbers. Out of … Read more
This tutorial is an introduction to the OpenCV library. Learn how to convert color channels, resize, blend, blur, and threshold images in Python. The OpenCV [1] library contains most of the functions we need for working with images. Handling images in programming requires a different intuition than handling text data. An image is made up … Read more
[toc] Introduction random is an in-built module in Python which generates pseudo-random numbers. Now, the random data generated by this module is not completely random. Instead it is pseudo-random, as mentioned previously. Note: A “True Random Number” can be generated by a TRNG (true random number generator) while a “pseudo-random number” is generated by a … Read more
[toc] Summary: The following methods allow us to check if all elements in a list are identical or not: Using list.count() Compare The Elements Using a For Loop Using The all() Method Using The set() Method Using Another List Slice And Compare Problem: Given a list; how will you identify if all elements within the … Read more
Learn to Love Your Lambda! Lambda functions in python are simple one-line functions without a name (and therefore called an anonymous function) that can take many arguments but will only evaluate a single expression. They’re fast, short, and simple and can help you write cleaner ‘more pythonic’ code. If like me you wanted to learn … Read more
Fills the string from the left with “0” characters. Minimal Example As you read over the explanations below, feel free to watch our video guide about this particular string method: Syntax and Explanation str.zfill(width) Fills the string from the left with “0” characters. width – the length of the resulting string. Although it works for … Read more
Returns an uppercase string version. Minimal Example As you read over the explanations below, feel free to watch our video guide about this particular string method: Syntax and Explanation str.upper() Returns an uppercase string version (copy) whereas each character is replaced with its uppercase variant: Application String Upper – Ignoring String Case An application of … Read more