Python

You Cannot Use Python Regex in startswith(). Do This Instead.

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I’m sitting in front of my computer refactoring Python code and have just thought of the following question: Can You Use a Regular Expression with the Python string.startswith() Method? The short answer is no. The string.startswith() method doesn’t allow regular expression inputs. And you don’t need it because regular expressions can already check if a … Read more

Python endswith() Tutorial – Can We Use Regular Expressions?

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While refactoring my Python code, I thought of the following question. Can You Use a Regular Expression with the Python endswith() Method? The simple answer is no because if you can use a regex, you won’t even need endswith()! Instead, use the re.match(regex, string) function from the re module. For example, re.match(“^.*(coffee|cafe)$”, tweet) checks whether … Read more

NumPy arange(): A Simple Illustrated Guide

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The np.arange() function appears in 21% of the 35 million Github repositories that use the NumPy library! This illustrated tutorial shows you the ins and outs of the NumPy arange function. So let’s get started! What’s the NumPy Arange Function? The np.arange([start,] stop[, step]) function creates a new NumPy array with evenly-spaced integers between start … Read more

A Recursive Pathfinder Algorithm in Python

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A simple and effective way to grow your computer science skills is to master the basics. Knowing the basics sets apart the great coders from the merely intermediate ones. One such basic area in computer science is graph theory, a specific subproblem of which—the pathfinder algorithm—we’ll address in this tutorial. So first things first: What … Read more

How to Calculate the Weighted Average of a Numpy Array in Python?

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Numpy Weighted Average np.average(array, axis=0, weights=[0.1,0.1,0.8])

Problem Formulation: How to calculate the weighted average of the elements in a NumPy array? Definition weighted average: Each array element has an associated weight. The weighted average is the sum of all array elements, properly weighted, divided by the sum of all weights. Here’s the problem exemplified: Quick solution: Before we discuss the solution … Read more

How to Calculate the Average of a NumPy 2D Array?

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NumPy is a popular Python library for data science focusing on arrays, vectors, and matrices. This article introduces the np.average() function from the NumPy library. When applied to a 1D array, this function returns the average of the array values. When applied to a 2D array, NumPy simply flattens the array. The result is the … Read more