To convert an integer i to a string with leading zeros so that it consists of 5 characters, use the format string f'{i:05d}’. The d flag in this expression defines that the result is a decimal value. The str(i).zfill(5) accomplishes the same string conversion of an integer with leading zeros. Challenge: Given an integer number. … Read more
The easiest way to extract numbers from a Python string s is to use the expression re.findall(‘\d+’, s). For example, re.findall(‘\d+’, ‘hi 100 alice 18 old 42’) yields the list of strings [‘100′, ’18’, ’42’] that you can then convert to numbers using int() or float(). There are some tricks and alternatives, so keep reading … Read more
π Disclaimer: NOT INVESTMENT ADVICE! In this short project, I’ll explain a Python trading bot I used for the purpose of arbitrage trading. I use Bitcoin BTC, but the arbitrage bot works better on illiquid and inefficiently priced coins — Bitcoin is usually far too liquid and efficiently priced for this to work. I also … Read more
In this article, you’ll learn how to make this beautiful and interesting animation using only Python, NumPy, and Matplotlib — nothing else: π But how does the Game of Life work – and what’s behind the classical visualization anyways? The Game of Life Conway’s Game of Life is a cellular automaton devised by the British … Read more
The Leibniz formula to calculate an approximation of the value of Ο is an infinite alternating series that adds and subtracts smaller and smaller terms of the form 1/x until it converges to the value of Ο/4. You can then multiply the result by 4 to obtain an approximation of Ο. Here’s the simple formula … Read more
Programming Challenge π¬ Challenge: Given a Python string. Find the longest substring for which holds that all of its characters are in alphabetical order so that the first character comes earlier in the alphabet than the second character, and so on. Here are three examples: You get the point. π Next, I’ll show you three … Read more
Coding Challenge π¬ Challenge: Given a string. How to find all palindromes in the string? For comprehensibility, allow me to quickly add a definition of the term palindrome: π‘ Definition: A palindrome is a sequence of characters that reads the same backward as forward such as ‘madam’, ‘anna’, or ‘101’. This article wants to give … Read more
Problem: Given a dictionary and a filter condition. How to filter a dictionary by … … key so that only those (key, value) pairs in the dictionary remain where the key satisfies the condition? … value so that only those (key, value) pairs remain where the value satisfies the condition? In this tutorial, you’ll learn … Read more
Coding Challenge π¬ Challenge: Given a string. How to find the longest palindrome in the string? For comprehensibility, allow me to quickly add a definition of the term palindrome: π‘ Definition: A palindrome is a sequence of characters that reads the same backward as forward such as ‘madam’, ‘anna’, or ‘101’. This article wants to … Read more
Problem Formulation and Solution Overview This article will show you how to find the most common element in a NumPy Array. To make it more interesting, we have the following running scenario: Carrie heard that Creative Prints is hiring a Python coder. They require the interviewee to answer several coding questions: one is to provide … Read more
The most Pythonic way to convert a list of floats fs to a list of strings is to use the one-liner fs = [str(x) for x in fs]. It iterates over all elements in the list fs using list comprehension and converts each list element x to a string value using the str(x) constructor. This … Read more
In a previous post, I explained how AlphaZero can play Connect Four. If you havenβt already, you can read the first part here. In this part 2, I will share how to write the code for the Monte Carlo Tree Search to play Connect Four below. First, we will import our libraries and define our … Read more