Python Dictionary – The Ultimate Guide

Python comes with several built-in data types. These are the foundational building blocks of the whole language. They have been optimised and perfected over many years. In this comprehensive tutorial, we will explore one of the most important: the dictionary (or dict for short). For your convenience, I’ve created a comprehensive 8000-word eBook which you … Read more

How to Sort a List of Tuples? – Most Pythonic Way!

Did you already try to sort a list of tuples? And when you saw the result, it wasn’t quite what you expected? Well, this happened to me when I went deeper into Python, and I suppose it also happened to you since you are looking for a solution. To me, this shows that you are … Read more

Introduction to Slicing in Python

Slicing is a concept to carve out a substring from a given string. Use slicing notation s[start:stop:step] to access every step-th element starting from index start (included) and ending in index stop (excluded). All three arguments are optional, so you can skip them to use the default values (start=0, stop=len(lst), step=1). For example, the expression … Read more

Python Numpy 101: How to Calculate the Row Variance of a Numpy 2D Array?

You can play with the following interactive Python code to calculate the variance of a 2D array (total, row, and column variance). Here’s another practical example: What is the output of this puzzle?*Advanced Level* (solution below) Numpy is a popular Python library for data science focusing on arrays, vectors, and matrices. This puzzle introduces a … Read more

How to Calculate Variance of Python NumPy Arrays?

Numpy is a popular Python library for data science focusing on arrays, vectors, and matrices. Did you already learn something new today? Let’s master the popular variance function in NumPy! Problem: How to calculate the variance of a NumPy array? Solution: To calculate the variance of a Python NumPy array x, use the function np.var(x). … Read more