Chris
If there is one clustering algorithm you need to know – whether you are a computer scientist, data scientist, or machine learning expert – it’s the K-Means algorithm. In this tutorial drawn from my book Python One-Liners, you’ll learn the general idea and when and how to use it in a single line of Python … Read more
The Python greater than (left>right) operator returns True when its left operand exceeds its right operand. When the left operand is smaller than or equal to the right operand, the > operator returns False. For example, 3>2 evaluates to True, but 2>3 and 3>3 both evaluate to False. Examples Let’s explore a couple of examples … Read more
This article explains how to calculate basic statistics such as average, standard deviation, and variance along an axis. We use the NumPy library for linear algebra computations. These three ways are very similar — if you understand one of them, you’ll understand all of them. TLDR; To average a NumPy array x along an axis, … Read more
What Are Python Operators? Python operators are special syntactical sugar to run basic operations without calling their respective methods. For example, you can use the + operator in a + b instead of the more clunky .add() method in a.add(b). Each operator has a unique symbol that is placed between the two arguments called operands. … Read more
In this article, you’ll learn about the division operators // and / in Python 2 and 3. You can check out the version in your Python script as shown here. A short visual overview of the division operator in Python 2 and 3: Assuming two integer values stored in variables a and b, there are … Read more
Problem Formulation Given a filename and an integer n. How to read the first n lines of the file in your Python script? Here’s an overview of the solutions: Method 1: Store Head in a List of Strings To read the first n lines of a given file and store each line in a list … Read more
Problem Formulation Given a JSON object stored in a file named “your_file.json” such as a list of dictionaries. 💬 How to append data such as a new dictionary to it? # File “your_file.json” (BEFORE) [{“alice”: 24, “bob”: 27}] # New entry: {“carl”: 33} # File “your_file.json” (AFTER) [{“alice”: 24, “bob”: 27}, {“carl”: 33}] Method 1: … Read more
Problem Formulation Given a TensorFlow variable created with tf.Variable(). As this variable may have changed during the training process (e.g., using assign()), you want to get the current value of it. How to accomplish this in TensorFlow? Sessions Are Gone in TensorFlow 2 In TensorFlow 1, computations were performed within Sessions. That’s why many people … Read more
Problem Formulation Given an integer number n. Get all divisors c of the number n so that c * i = n for another integer i. The desired output format is a list of integers (divisors). Here are a couple of examples: n = 10 # Output: [1, 2, 5, 10] n = 13 # … Read more
Method overriding vs overloading in Python—what’s the difference? If you’re short on time—here it is: Method overloading: creating a method that can be called with different arguments such as m() and m(1, 2, 3). Method overriding: overwriting the functionality of a method defined in a parent class. In method overloading, methods in a given class … Read more
Hacking Alexa’s Voice Recordings After David’s mother passed away, he wanted to hear her voice again. As she used Amazon Alexa, he figured, he could download the voice recordings from the Alexa device. But Amazon didn’t provide an interface for it. Fortunately he found this project online: [Cool Project] Hacking Alexa’s Voice Recordings After following … Read more
Problem Formulation Given an image stored at image.jpeg, a target width and height in pixels, and a target starting point (upper-left) x and y in the coordinate system. How to crop the given image in Python OpenCV so that the resulting image has width * height size? Here’s an example of how the original image … Read more