Python Set update()

Python’s set.update(set_1, set_2, …) performs the union of all involved sets and updates the set on which it is called. It adds all members of the set argument(s) to the set on which it is called. For example, s.update({1, 2}) adds elements 1 and 2 to the original set s. Here’s a minimal example that … Read more

Python Set Methods

All set methods are called on a given set. For example, if you created a set s = {1, 2, 3}, you’d call s.clear() to remove all elements of the set. We use the term “this set” to refer to the set on which the method is executed. add() Add an element to this set … Read more

Python Dash Book

We’ve just launched the first in-depth Python Plotly Dash book with the world’s #1 computer science book publisher NoStarch. You can order Python Dash on Amazon or NoStarch directly. Book Description A swift and practical introduction to building interactive data visualization apps in Python, known as dashboards. You’ve seen dashboards before; think election result visualizations … Read more

How to Dynamically Create a Function in Python?

Problem Formulation There are different variants of this problem that all ask the same thing: How to create a function dynamically in Python? How to define a function at runtime? How to define a function programmatically? How to create a function from a string? There are many ways to answer these questions—most web resources provide … Read more

How to Display an Image as Grayscale in Python Matplotlib?

How to Display an Image as Grayscale in Python Matplotlib? You can convert a given image to a grayscale image using four simple steps: Import the PIL and Matplotlib libraries Open the image with PIL.Image.open(filename). Convert the opened image to grayscale using img.convert(“L”) with greyscale mode “L”. Display the image using Matplotlib’s plt.imshow(gray_img, cmap=’gray’) function. … Read more

Your First Dash App – How to Get Started in 4 Minutes or Less

Minute 1: Install Dash Type the following command in your terminal/shell. Windows, macOS: Linux, Ubuntu: Minute 2: Create Minimal Dash Project File “app.py” Copy&paste the code into a new file called β€œapp.py” in a folder – with path /path/to/dash_app/app.py: Minute 3: Run Dash App Open a terminal or shell in the /path/to/dash_app/ and run python … Read more

How to Convert a String List to an Integer List in Python

The most Pythonic way to convert a list of strings to a list of ints is to use the list comprehension [int(x) for x in strings]. It iterates over all elements in the list and converts each list element x to an integer value using the int(x) built-in function. This article shows you the simplest … Read more

How to Calculate the Levenshtein Distance in Python?

Levensthein Distance

After studying this article, you will know exactly how to calculate the edit distance in Python. Learning requires opening your knowledge gap first. So let’s do this. What is the output of the following Python puzzle showing you a concise code snippet to calculate the edit distance in Python? (source) Python Source Code Now, this … Read more

Conditional Indexing: How to Conditionally Select Elements in a NumPy Array?

Selective Indexing

Problem Description: You have a Numpy array. You want to select specific elements from the array. But neither slicing nor indexing seem to solve your problem. What can you do? In this short tutorial, I show you how to select specific Numpy array elements via Boolean matrices. A feature called conditional indexing or selective indexing. … Read more

How to Convert a String List to a Float List in Python

The most Pythonic way to convert a list of strings to a list of floats is to use the list comprehension floats = [float(x) for x in strings]. It iterates over all elements in the list and converts each list element x to a float value using the float(x) built-in function. This article shows you … Read more

How to Convert an Integer List to a Float List in Python

The most Pythonic way to convert a list of integers ints to a list of floats is to use the list comprehension expression floats = [float(x) for x in ints]. It iterates over all elements in the list ints using list comprehension and converts each list element x to a float value using the float(x) … Read more