My code from working with THE BIG BOOK OF SMALL PYTHON PROJECTS. The projects are in alphabetical order but youll notice stars ⭐⭐⭐ next to the more complex projects. more stars being more complex
Install Python 3 using Homebrew or your fav package manager:
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Install Homebrew (if you haven't already):
- Run the following command to install Homebrew:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
- Run the following command to install Homebrew:
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Install Python 3:
- Run the following command to install Python 3:
brew install python
- Run the following command to install Python 3:
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Verify the Installation:
- After the installation is complete, run the following command to ensure Python 3 is installed correctly:
python3 --version
- You should see output indicating the version of Python 3 that is installed, such as:
Python 3.x.x
- After the installation is complete, run the following command to ensure Python 3 is installed correctly:
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Git Clone
- Use Git Clone to get the directory of projects
git clone git@github.com:GnarlyLasagna/81-python-projects.git
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Cd in and use script -Cd into the directory of the desired project:
cd bagelspython3 bagels.py
- Bagels
- Birthday Paradox
- Bitmap Message
- Blackjack
- Bouncing DVD Logo
- Caesar Cipher
- Caesar Hacker
- Calendar Maker
- Carrot In A Box
- Cho-Han
- Clickbait Headline Generator
- Collatz Sequence
- Conways Game Of Life
- Countdown
- Deep Cave
- Diamonds
- Dice Math
- Dice Roller
- Digital Clock
- Digital Stream
- DNA Visualization
- Ducklings
- Etching Drawer
- Factor Finder
- Fast Draw
- Fibonacci
- Fish Tank
- Flooder
- Forest Fire Sim
- Four In A Row
- Guess The Number
- Gullible
- Hacking Minigame
- Hangman And Guillotine
- Hex Grid
- Hourglass
- Hungry Robots
- J'accuse!
- Langton's Ant
- Leetspeak
- Lucky Stars
- Magic Fortune Ball
- Mancala
- Maze Runner 2D
- Maze Runner 3D
- Million Dice Roll Statistics Simulator
- Mondrian Art Generator
- Monty Hall Problem
- Multiplication Table
- Ninety-Nine Bottles
- Ninety-Nniine Boottels
- Numeral System Counters
- Periodic Table Of The Elements
- Pig Latin
- Powerball Lottery
- Prime Numbers
- Progress Bar
- Rainbow
- Rock Paper Scissors
- Rock Paper Scissors (Always Win Version)
- Rot13 Cipher
- Rotating Cube
- Royal Game of Ur
- Seven-Segment Display Module
- Shining Carpet
- Simple Substitution Cipher
- Sine Message
- Sliding tile puzzle
- Snail race
- Soroban Japanese Abacus
- Sound Mimic
- Spongecase
- Sudoku puzzle
- Text-to-speech talker
- Three-card monte
- Tic-tac-toe
- Tower of Hanoi
- Trick Questions
- Twenty Fourty-Eight
- Vigenere Cipher
- Water Bucket Puzzle
In Bagels, a deductive logic game, you must guess a secret three-digit number based on clues. The game offers one of the following hints in response to your guess: “Pico” when your guess has a correct digit in the wrong place, “Fermi” when your guess has a correct digit in the correct place, and “Bagels” if your guess has no correct digits. You have 10 tries to guess the secret number.
The Birthday Paradox, also called the Birthday Problem, is the surprisingly high probability that two people will have the same birthday even in a small group of people. In a group of 70 people, there’s a 99.9 percent chance of two people having a matching birthday. But even in a group as small as 23 people, there’s a 50 percent chance of a matching birthday. This program performs several probability experiments to determine the percentages for groups of different sizes. We call these types of experiments, in which we conduct multiple random trials to understand the likely outcomes, Monte Carlo experiments.
This program uses a multiline string as a bitmap, a 2D image with only two possible colors for each pixel, to determine how it should display a message from the user. In this bitmap, space characters represent an empty space, and all other characters are replaced by characters in the user’s message. The provided bitmap resembles a world map, but you can change this to any image you’d like. The binary simplicity of the space-or-message-characters system makes it good for begin- ners. Try experimenting with different messages to see what the results look like!
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Blackjack, also known as 21, is a card game where players try to get as close to 21 points as possible without going over. This program uses images drawn with text characters, called ASCII art. American Standard Code for Information Interchange (ASCII) is a mapping of text characters to numeric codes that computers used before Unicode replaced it.
If you are of a certain age, you’ll remember those ancient technological devices called DVD players. When not playing DVDs, they would display a diagonally traveling DVD logo that bounced off the edges of the screen. This program simulates this colorful DVD logo by making it change direction each time it hits an edge. We’ll also keep track of how many times a logo hits a corner of the screen. This creates an interesting visual animation to look at, especially for the magical moment when a logo lines up perfectly with a corner.
You can’t run this program from your integrated development environment (IDE) or editor because it uses the bext module. Therefore, it must be run from the Command Prompt or Terminal in order to display correctly. You can find more information about the bext module at https://pypi.org/ project/bext/.
The Caesar cipher is an ancient encryption algorithm used by Julius Caesar. It encrypts letters by shifting them over by a certain number of places in the alphabet. We call the length of shift the key. For example, if the key is 3, then A becomes D, B becomes E, C becomes F, and so on. To decrypt the message, you must shift the encrypted letters in the opposite direction. This program lets the user encrypt and decrypt messages according to this algorithm.
In modern times, the Caesar cipher isn’t very sophisticated, but that makes it ideal for beginners. The program in Project 7, “Caesar Hacker,” can brute-force through all 26 possible keys to decrypt messages, even if you don’t know the original key. Also, if you encrypt the message with the key 13, the Caesar cipher becomes identical to Project 61, “ROT 13 Cipher.”
Learn more about the Caesar cipher at https://en.wikipedia.org/wiki/Caesar_ cipher. If you’d like to learn about ciphers and code breaking in general, you can read my book Cracking Codes with Python (No Starch Press, 2018; https:// nostarch.com/crackingcodes/).
This program can hack messages encrypted with the Caesar cipher from Project 6, even if you don’t know the key. There are only 26 possible keys for the Caesar cipher, so a computer can easily try all possible decryptions and display the results to the user. In cryptography, we call this technique a brute-force attack.
This program generates printable text files of monthly calendars for the month and year you enter. Dates and calendars are a tricky topic in programming because there are so many different rules for determining the number of days in a month, which years are leap years, and which day of the week a particular date falls on. Fortunately, Python’s datetime module handles these details for you. This program focuses on generating the multiline string for the monthly calendar page.
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This is a simple and silly bluffing game for two human players. Each player has a box. One box has a carrot in it, and each player wants to have the carrot. The first player looks in their box and then tells the second player they either do or don’t have the carrot. The second
Cho-han is a dice game played in gambling houses of feudal Japan. Two six-sided dice are rolled in a cup, and gamblers must guess if the sum is even (cho) or odd (han). The house takes a small cut of all winnings. The simple random number generation and basic math used to determine odd or even sums make this project especially suitable for beginners. More information about Cho-han can be found at https://en.wikipedia.org/wiki/ Cho-han.
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Our website needs to trick people into looking at advertisements! But coming up with creative, original content is too hard. Luckily, with the clickbait headline generator, we can make a computer come up with millions of outrageous fake headlines. They’re all low quality, but readers don’t seem to mind. This program generates as many headlines as you need from a Mad Libs–style template.
The Collatz sequence, also called the 3n + 1 problem, is the simplest impossible math problem. (But don’t worry, the program itself is easy enough for beginners.) From a starting number, n, follow three rules to get the next number in the sequence:
- If n is even, the next number n is n / 2.
- If n is odd, the next number n is n * 3 + 1.
- If n is 1, stop. Otherwise, repeat.
Conway’s Game of Life is a cellular automata simulation that follows simple rules to create interesting patterns. It was invented by mathematician John Conway in 1970 and popularized by Martin Gardner’s “Mathematical Games” column in Scientific American. Today, it’s a favorite among programmers and computer scientists, though it’s more an interesting visualization than a true “game.” The two dimensional board has a grid of “cells,” each of which follows three simple rules: • Living cells with two or three neighbors stay alive in the next step of the simulation. • Dead cells with exactly three neighbors become alive in the next step of the simulation. • Any other cell dies or stays dead in the next step of the simulation.
The living or dead state of the cells in the next step of the simulation depends entirely on their current state. The cells don’t “remember” any older states. There is a large body of research regarding the patterns that these simple rules produce. Tragically, Professor Conway passed away of complications from COVID-19 in April 2020. More information about Conway’s Game of Life can be found at https://en.wikipedia.org/wiki/ Conway%27s_Game_of_Life, and more information about Martin Gardner at https://en.wikipedia.org/wiki/Martin_Gardner.
This program displays a digital timer that counts down to zero. Rather than render numeric characters directly, the sevseg.py module from Project 64, “Seven-Segment Display Module,” generates the drawings for each digit. You must create this file before the Countdown program can work. Then, set the countdown timer to any number of seconds, minutes, and hours you like. This program is similar to Project 19, “Digital Clock.”
This program is an animation of a deep cave that descends forever into the earth. Although short, this program takes advantage of the scrolling nature of the computer screen to produce an interesting and unending visualization, proof that it doesn’t take much code to produce something fun to watch. This program is similar to Project 58, “Rainbow.”
This program features a small algorithm for drawing ASCII-art diamonds of various sizes. It contains functions for drawing either an outline or filled-in-style diamond of the size you dictate. These functions are good practice for a beginner; try to understand the pattern behind the diamond drawings as they increase in size.
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This math quiz program rolls two to six dice whose sides you must add up as quickly as possible. But this program operates as more than just automated flash cards; it draws the faces of the dice to random places on the screen. The ASCII-art aspect adds a fun twist while you practice arithmetic.
Dungeons & Dragons and other tabletop role-playing games use special dice that can have 4, 8, 10, 12, or even 20 sides. These games also have a specific notation for indicating which dice to roll. For example, 3d6 means rolling three six-sided dice, while 1d10+2 means rolling one ten-sided die and adding a two-point bonus to the roll. This program simulates this dice rolling, in case you forgot to bring your own. It can also simulate rolling dice that don’t physically exist, such as a 38-sided die.
This program displays a digital clock with the current time. Rather than render numeric characters directly, the sevseg.py module from Project 64, “Seven-Segment Display Module,” generates the drawings for each digit. This program is similar to Project 14, “Countdown.”
This program mimics the “digital stream” visualization from the science fiction movie The Matrix. Random beads of binary “rain” stream up from the bottom of the screen, creating a cool, hacker-like visualization. (Unfortunately, due to the way text moves as the screen scrolls down, it’s not possible to make the streams fall downward without using a module such as bext.)
Deoxyribonucleic acid is a tiny molecule that exists in every cell of our bodies and contains the blueprint for how our bodies grow. It looks like a double helix (a sort of twisted ladder) of pairs of nucleotide molecules: guanine, cytosine, adenine, and thymine. These are represented by the letters G, C, A, and T. DNA is a long molecule; it’s microscopic, but if it were stretched out, its 3 billion base pairs would be 2 meters long! This program is a simple animation of DNA.
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This program creates a scrolling field of ducklings. Each duckling has slight variations: they can face left or right and have two different body sizes, four types of eyes, two types of mouths, and three positions for their wings. This gives us 96 different possible variations, which the Ducklings program produces endlessly.
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When you move a pen point around the screen with the WASD keys, the etching drawer forms a picture by tracing a continuous line, like the Etch A Sketch toy. Let your artistic side break out and see what images you can create! This program also lets you save your drawings to a text file so you can print them out later. Plus, you can copy and paste the WASD movements of other drawings into this program, like the WASD commands for the Hilbert Curve fractal presented on lines 6 to 14 of the source code.
A number’s factors are any two other num- bers that, when multiplied with each other, produce the number. For example, 2 × 13 = 26, so 2 and 13 are factors of 26. Also, 1 × 26 = 26, so 1 and 26 are also factors of 26. Therefore, we say that 26 has four factors: 1, 2, 13, and 26. If a number only has two factors (1 and itself), we call that a prime number. Otherwise, we call it a composite number. Use the factor finder to discover some new prime numbers! (Hint: Prime numbers always end with an odd number that isn’t 5.) You can also have the computer calculate them with Project 56, “Prime Numbers.”
This program tests your reaction speed: press ENTER as soon as you see the word DRAW. But careful, though. Press it before DRAW appears, and you lose. Are you the fastest keyboard in the west?
The Fibonacci sequence is a famous mathematical pattern credited to Italian mathematician Fibonacci in the 13th century (though others had discovered it even earlier). The sequence begins with 0 and 1, and the next number is always the sum of the previous two numbers. The sequence continues forever: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987 . . . The Fibonacci sequence has applications in music composition, stock market prediction, the pattern of florets in the head of sunflowers, and many other areas. This program lets you calculate the sequence as high as you are willing to go. More information about the Fibonacci sequence can be found at https://en.wikipedia.org/wiki/Fibonacci_number.
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Watch your own virtual fish in a virtual fish tank, complete with air bubblers and kelp plants. Each time you run the program, it randomly generates the fish using different fish types and colors. Take a break and enjoy the calm serenity of this software aquarium, or try programming in some virtual sharks to terrorize its inhabitants! You can’t run this program from your IDE or editor. This program uses the bext module and must be run from the Command Prompt or Terminal in order to display correctly. More information about the bext module can be found at https://pypi.org/project/bext/.
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Flooder is a colorful game where a player tries to fill the board with a single color by changing the color of the tile in the upper-left corner. This new color spreads to all neighboring tiles that matched the original color. It’s similar to the Flood It mobile game. This program also has a colorblind mode, which uses shapes instead of flat colored tiles. It relies on the recursive flood fill algorithm to paint the board and works similarly to the “paint bucket” or “fill” tool in many painting applications.
This simulation shows a forest whose trees are constantly growing and then being burned down. On each step of the simulation, there is a 1 percent chance that a blank space grows into a tree and a 1 percent chance that a tree is struck by lightning and burns. Fires will spread to adjacent trees, so a densely packed forest is more likely to suffer a larger fire than a sparsely packed one. This simulation was inspired by Nicky Case’s Emoji Sim at http://ncase.me/simulating/model/.
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In this classic tile-dropping board game for two players, you must try to get four of your tiles in a row horizontally, vertically, or diagonally, while preventing your opponent from doing the same. This program is similar to Connect Four.
Guess the Number is a classic game for beginners to practice basic programming techniques. In this game, the computer thinks of a random number between 1 and 100. The player has 10 chances to guess the number. After each guess, the computer tells the player if it was too high or too low.
In this short and simple program, you can learn the secret and subtle art of keeping a gullible person busy for hours. I won’t spoil the punch line here. Copy the code and run it for yourself. This project is great for beginners, whether you’re smart or . . . not so smart.
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In this game, the player must hack a computer by guessing a seven-letter word used as the secret password. The computer’s memory banks display the possible words, and the player is given hints as to how close each guess was. For example, if the secret password is MONITOR but the player guessed CONTAIN, they are given the hint that two out of seven letters were correct, because both MONITOR and CONTAIN have the letter O and N as their second and third letter. This game is similar to Project 1, “Bagels,” and the hacking minigame in the Fallout series of video games.
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This classic word game has the player guess the letters to a secret word. For each incorrect letter, another part of the hangman is drawn. Try to guess the complete word before the hangman completes. The secret words in this version are all animals like RABBIT and PIGEON, but you can replace these with your own set of words.
This short program produces a tessellated image of a hexagonal grid, similar to chicken wire. It shows that you don’t need a lot of code to make something interesting. A slightly more complicated variation of this program is Project 65, “Shining Carpet.” Note that this program uses raw strings, which prefix the opening quote with a lowercase r so that the backslashes in the string aren’t interpreted as escape characters.
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This visualization program has a rough physics engine that simulates sand falling through the small aperture of an hourglass. The sand piles up in the bottom half of the hourglass; then the hourglass is turned over so the process repeats.
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You are trapped in a maze with hungry robots! You don’t know why robots need to eat, but you don’t want to find out. The robots are badly programmed and will move directly toward you, even if blocked by walls. You must trick the robots into crashing into each other (or dead robots) without being caught. You have a personal teleporter device that can send you to a random new place, but it only has enough battery for two trips. Also, you and the robots can slip through corners!
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You are the world-famous detective Mathilde Camus. Zophie the cat has gone missing, and you must sift through the clues. Suspects either always tell lies or always tell the truth. Will you find Zophie the cat in time and accuse the guilty party? In this game, you take a taxi to different locations around the city. At each location is a suspect and an item. You can ask suspects about other suspects and items, compare their answers with your own exploration notes, and determine if they are lying or telling the truth. Some will know who has catnapped Zophie (or where she is, or what item is found at the location of the kidnapper), but you must determine if you can believe them. You have five minutes to find the criminal but will lose if you make three wrong accusations. This game is inspired by Homestar Runner’s “Where’s an Egg?” game.
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Langton’s Ant is a cellular automata simulation on a two-dimensional grid, similar to Project 13, “Conway’s Game of Life.” In the simulation, an “ant” begins on a square that is one of two colors. If the space is the first color, the ant switches it to the second color, turns 90 degrees to the right, and moves forward one space. If the space is the second color, the ant switches it to the first color, turns 90 degrees to the left, and moves forward one space. Despite the very simple set of rules, the simulation displays complex emergent behavior. Simulations can feature multiple ants in the same space, causing interesting interactions when they cross paths with each other. Langton’s Ant was invented by computer scientist Chris Langton in 1986. More information about Langton’s Ant can be found at https://en.wikipedia.org/wiki/ Langton%27s_ant.
There’s no better way to demonstrate your mad hacker skills than by replacing letters in your text with numbers: m4d h4x0r 5k1llz!!! This word program automatically converts plain English into leetspeak, the coolest way to talk online. Or at least it was in 1993. It takes a while to get used to, but with some practice, you’ll eventually be able to read leetspeak fluently. For example, 1t +@]<3s 4 w|-|1le +o g37 ||s3|) 70, b||+ y0u (an 3/3nt||/-\lly r3a|) l33t$peak phl||3n+ly. Leetspeak may be hard to read at first, but the program itself is simple and good for beginners. More information about leetspeak can be found at https://en.wikipedia.org/wiki/Leet.
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In this push-your-luck game, you roll dice to collect stars. The more you roll, the more stars you can get, but if you get three skulls you lose everything! This quick multiplayer game can support as many players as you want, making it ideal for parties. On your turn, you pull three random dice from the dice cup and roll them. You can roll Stars, Skulls, and Question Marks. If you end your turn, you get one point per Star. If you choose to roll again, you keep the Question Marks and pull new dice to replace the Stars and Skulls. If you collect three Skulls, you lose all your Stars and end your turn. When a player gets 13 points, everyone else gets one more turn before the game ends. Whoever has the most points wins. There are six gold dice, four silver dice, and three bronze dice in the cup. Gold dice have more Stars, bronze dice have more Skulls, and silver is even.
The Magic Fortune Ball can predict the future and answer your yes/no questions with 100 percent accuracy using the power of Python’s random number module. This program is similar to a Magic 8 Ball toy, except you don’t have to shake it. It also features a function for slowly printing text strings with spaces in between each character, giving the messages a spooky, mysterious effect. Most of the code is dedicated to setting the eerie atmosphere. The program itself simply selects a message to display in response to a random number.
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The board game Mancala is at least 2,000 years old, making it almost as old as Project 63, “Royal Game of Ur.” It is a “seed-sowing” game in which two players select pockets of seeds to spread across the other pockets on the board while trying to collect as many in their store as possible. There are several variants of this game across different cultures. The name comes from the Arab word naqala, meaning “to move.” To play, grab the seeds from a pit on your side of the board and place one in each subsequent pit, going counterclockwise and skipping your opponent’s store. If your last seed lands in an empty pit of yours, move the opposite pit’s seeds into that pit. If the last placed seed is in your store, you get a free turn. Mancala 207 The game ends when all of one player’s pits are empty. The other player claims the remaining seeds for their store, and the winner is the one with the most seeds. More information about Mancala and its variants can be found at https://en.wikipedia.org/wiki/Mancala.
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This two-dimensional maze runner shows the player a top-down, bird’s-eye view of a maze file you create in a text editor, such as the IDE you use to write your .py files. Using the WASD keys, the player can move up, left, down, and right, respectively, to navigate the @ symbol toward the exit marked by the X character. To make a maze file, open a text editor and create the following pattern. Don’t type the numbers along the top and left side; they are only there for reference: 123456789 1######### 2#S# # # # 3######### 4# # # # # 5#########
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This three-dimensional maze runner provides the player with a first-person view from inside a maze. Try to find your way out! You can generate maze files by following the instructions in Project 44, “Maze Runner 2D,” or by downloading maze files from https://invpy.com/mazes/.
When you roll two six-sided dice, there’s a 17 percent chance you’ll roll a 7. That’s much better than the odds of rolling a 2: just 3 percent. That’s because there’s only one combination of dice rolls that gives you 2 (the one that occurs when both dice roll a 1), but many combinations add up to seven: 1 and 6, 2 and 5, 3 and 4, and so on. But what about when you roll three dice? Or four? Or 1,000? You could mathematically calculate the theoretical probabilities, or you can have the computer roll a number of dice one million times to empirically figure them out. This program takes that latter approach. In this program, you tell the computer to roll N dice one million times and remember the results. It then displays the percentage chance of each sum. This program does a massive amount of computation, but the computation itself isn’t hard to understand.
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Piet Mondrian was a 20th-century Dutch painter and one of the founders of neoplasticism, an abstract art movement. His most iconic paintings relied on blocks of primary colors (blue, yellow, red), black, and white. Using a minimalist approach, he separated these colors with horizontal and vertical elements. This program generates random paintings that follow Mondrian’s style. You can find out more about Piet Mondrian at https://en.wikipedia.org/wiki/ Piet_Mondrian.
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The Monty Hall Problem illustrates a surprising fact of probability. The problem is loosely based on the old game show Let’s Make a Deal and its host, Monty Hall. In the Monty Hall Problem, you can pick one of three doors. Behind one door is a prize: a new car. Each of the other two doors opens onto a worthless goat. Say you pick Door #1. Before the door you choose is opened, the host opens another door (either #2 or #3), which leads to a goat. You can choose to either open the door you originally picked or switch to the other unopened door. It may seem like it doesn’t matter if you switch or not, but your odds do improve if you switch doors! This program demonstrates the Monty Hall problem by letting you do repeated experiments. To understand why your odds improve, consider a version of the Monty Hall Problem with one thousand doors instead of three. You pick one door, and then the host opens 998 doors, which all reveal goats. The only two Monty Hall Problem 239 doors that are unopened are the one you selected and one other door. If you correctly picked the car door to begin with (a 1 in a 1,000 chance), then the host left a random goat door closed. If you picked a goat door (a 999 in a 1,000 chance), the host specifically chose the car door to leave closed. The choice of which doors to open isn’t random; the host knows to leave the car door closed. It’s almost certain that you didn’t pick the car door to begin with, so you should switch to the other door. Another way to think of it is that you have 1,000 boxes and one box contains a prize. You guess which box the prize is in and the host puts it in your hands. Do you think the prize is in your box or one of the 999 other boxes? You don’t need the host to open 998 of the 999 boxes that don’t contain a prize; the amount of choice is the same as with the 1,000 doors. The odds that you guessed correctly in the beginning are 1 in 1,000, while the odds that you did not (and that the prize is in one of the other boxes) is a near certain 999 in 1,000. More information about the Monty Hall Problem can be found at https://en.wikipedia.org/wiki/Monty_Hall_problem.
This program generates a multiplication table from 0 × 0 to 12 × 12. While simple, it provides a useful demonstration of nested loops.
“Ninety-Nine Bottles” is a folk song of undetermined origin known for its length and repetitiveness. The lyrics go, “Ninety- nine bottles of milk on the wall, ninety-nine bottles of milk. Take one down, pass it around, ninety-eight bottles of milk on the wall.” As the lyrics repeat, the number of bottles falls from ninety-eight to ninety-seven, then from ninety-seven to ninety-six, until it reaches zero: “One bottle of milk on the wall, one bottle of milk. Take it down, pass it around, no more bottles of milk on the wall!” Luckily for us, computers are excellent at performing repetitive tasks, and this program reproduces all of the lyrics programmatically. An extended version of this program is in Project 51, “niNety-nniinE BoOttels.”
In this version of the song “Ninety-Nine Bottles,” the program introduces small imperfections in each stanza by either removing a letter, swapping the casing of a letter, transposing two letters, or doubling a letter. As the song continues to play, these mutations add up, resulting in a very silly song. It’s a good idea to try Project 50, “Ninety-Nine Bottles,” before attempting this one.
We’re used to counting in the decimal numeral system, which uses 10 digits: 0 through 9. This system likely developed because humans counted on their fingers, and most people have 10 fingers. But other number systems exist. Computers make use of binary, a numeral system with only two digits, 0 and 1. Programmers also sometimes use hexadecimal, which is a base-16 numeral system that uses the digits 0 to 9 but also extends into the letters A to F. We can represent any number in any numeral system, and this program displays a range of numbers in decimal, binary, and hexadecimal.
The periodic table of the elements organizes all known chemical elements into a single table. This program presents this table and lets the player access additional information about each element, such as its atomic number, symbol, melting point, and so on. I compiled this information from Wikipedia and stored it in a file called periodictable.csv that you can download from https://inventwithpython.com/periodictable.csv.
Pig Latin is a word game that transforms English words into a parody of Latin. In Pig Latin, if a word begins with a consonant, the speaker removes this letter and puts it at the end, followed by “ay.” For example, “pig” becomes “igpay” and “latin” becomes “atinlay.” Otherwise, if the word begins with a vowel, the speaker simply adds “yay” to the end of it. For example, “elephant” becomes “elephantyay” and “umbrella” becomes “umbrellayay.”
The Powerball Lottery is an exciting way to lose small amounts of money. If you purchase a $2 ticket, you can pick six numbers: five drawn from 1 to 69, and a sixth “Powerball” number drawn from 1 to 26. The order of the num- bers doesn’t matter. If the lottery selects your six numbers, you win $1.586 billion dollars! Except you won’t win, because your odds are 1 in 292,201,338. But if you spent $200 on 100 tickets, your odds would be . . . 1 in 2,922,013. You won’t win that either, but at least you’ll lose 100 times as much money. The more you like losing money, the more fun the lottery is! To help you visualize how often you won’t win the lottery, this program simulates up to one million Powerball drawings and then compares them with the numbers you picked. Now you can have all the excitement of losing the lottery without spending money.
Fun fact: every set of six numbers is just as likely to win as any other. So the next time you want to buy a lottery ticket, pick the numbers 1, 2, 3, 4, 5, and 6. Those numbers are just as likely to come up as a more complex set.
A prime number is a number that is evenly divisible only by one and itself. Prime numbers have a variety of practical applications, but no algorithm can predict them; we must calculate them one at a time. However, we do know that there is an infinite number of prime numbers to be discovered. This program finds prime numbers through brute-force calculation. Its code is similar to Project 24, “Factor Finder.” (Another way to describe a prime number is that one and the number itself are its only factors.) You can find out more about prime numbers from https://en.wikipedia.org/wiki/ Prime_number.
A progress bar is a visual element that shows how much of a task has been completed. Progress bars are often used alongside downloading files or software installations. This project creates a getProgressBar() function that returns a progress bar string based on the arguments passed to it. It simulates a downloading file, but you can reuse the progress bar code in your own projects.
Rainbow is a simple program that shows a colorful rainbow traveling back and forth across the screen. The program makes use of the fact that when new lines of text appear, the existing text scrolls up, causing it to look like it’s moving. This program is good for beginners, and it’s similar to Project 15, “Deep Cave.”
In this version of the two-player hand game also known as Rochambeau or jan-ken-pon, the player faces off against the computer. You can pick either rock, paper, or scissors. Rock beats scissors, scissors beats paper, and paper beats rock. This program adds some brief pauses for suspense. For a variation of this game, see Project 60, “Rock Paper Scissors (Always-Win Version).”
This variant of Rock Paper Scissors is identical to Project 59, “Rock Paper Scissors,” except the player will always win. The code selecting the computer’s move is set so that it always chooses the losing move. You can offer this game to your friends, who may be excited when they win . . . at first. See how long it takes before they catch on to the fact that the game is rigged in their favor.
The ROT13 cipher, one of the simplest encryption algorithms, stands for “rotate 13 spaces.” The cypher represents the letters A to Z as the numbers 0 to 25 in such a way that the encrypted letter is 13 spaces from the plaintext letter: A becomes N, B becomes O, and so on. The encryption process is identical to the decryption process, making it trivial to program. However, the encryption is also trivial to break. Because of this, you’ll most often find ROT13 used to conceal non-sensitive information, such as spoilers or trivia answers, so it’s not read unintentionally. More information about the ROT13 cipher can be found at https://en.wikipedia.org/ wiki/ROT13. If you’d like to learn about ciphers and code breaking more generally, you can read my book Cracking Codes with Python (No Starch Press, 2018; https://nostarch.com/crackingcodes/).
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This project features an animation of a 3D cube rotating using trigonometric functions. You can adapt the 3D point rotation math and the line() function in your own animation programs. Although the block text characters we’ll use to draw the cube don’t look like thin, straight lines, this kind of drawing is called a wireframe model because it renders only the edges of an object’s surfaces. Figure 62-1 shows the wireframe model for a cube and an icosphere, a rough sphere made of triangles.
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The Royal Game of Ur is a 5,000-year-old game from Mesopotamia. Archeologists rediscovered the game in the Royal Cemetery at Ur, in modern-day southern Iraq, during exca- vations between 1922 and 1934. The rules were reconstructed from the game board (shown in Figure 63-1) and a Babylonian clay tablet, and they’re similar to Parcheesi. You’ll need both luck and skill to win.
Two players each begin with seven tokens in their home, and the first player to move all seven to the goal is the winner. Players take turns throw- ing four dice. These dice are four-pointed pyramid shapes called tetrahe- drons. Each die has two marked points, giving an even chance that the dice come up marked or unmarked. Instead of dice, our game uses coins whose heads act as the marked point. The player can move a token one space for each marked point that comes up. This means they can move a single token between zero and four spaces, though they’re most likely to roll two spaces. The tokens travel along the path indicated in Figure 63-2. Only one token may exist on a space at a time. If a token lands on an opponent’s token while in the shared middle path, the opponent’s token is sent back home. If a token lands on the middle flower square, it is safe from being landed on. If a token lands on any of the other four flower tiles, the player gets to roll again. Our game will represent the tokens with the letters X and O.
A seven-segment display is a type of LCD component used to display numbers in pocket calculators, microwave ovens, and other small electronic devices. Through differ- ent combinations of seven line-shaped segments in an LCD, a seven-segment display can represent the digits 0 through 9. They look like this:
__ __ __ __ __ __ __ __
| | | __| __| |__| |__ |__ | |__| |__|
|__| | |__ __| | __| |__| | |__| __|
The benefit of this program is that other programs can import it as a module. Project 14, “Countdown,” and Project 19, “Digital Clock,” import the sevseg.py file so they can use its getSevSegStr() function. You can find more information about seven-segment displays and other variations at https://en.wikipedia.org/wiki/Seven-segment_display.
The Shining, a 1980 psychological horror film directed by Stanley Kubrick, takes place at the haunted Overlook Hotel. The hotel carpet’s hexagonal design became an iconic part of this famous movie. The carpet features alternating and interlocking hexagons whose mesmerizing effect is well-suited for such an unnerving film. The short program in this project, similar to Project 35, “Hex Grid,” prints this repetitive pattern on the screen. Note that this program uses raw strings, which prefix the opening quote with a lowercase r, so that the backslashes in the string aren’t inter- preted as escape characters.
The Simple Substitution Cipher substitutes one letter for another. Since there are 26 possible substitutions for the letter A, 25 possible substitutions for B, 24 for C, and so on, the total number of possible keys is 26 × 25 × 24 × 23 × . . . × 1, or 403,291,461,126,605,635,584,000,000 keys! That’s far too many keys for even a supercomputer to brute force, so the code-breaking method used in Project 7, “Caesar Hacker,” can’t be used against the simple cipher. Unfortunately, devious attackers can take advantage of known weakness to break the code. If you’d like to learn more about ciphers and code breaking, you can read my book Cracking Codes with Python (No Starch Press, 2018; https://nostarch.com/ crackingcodes/).
This program displays a message of the user’s choice in a wavy pattern as the text scrolls up. It accomplishes this effect with math.sin(), which implements the trigonometric sine wave function. But even if you don’t understand the math, this program is rather short and easy to copy.
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This classic puzzle relies on a 4 × 4 board with 15 numbered tiles and one free space. The objective is to slide the tiles until the numbers are in the correct order, going left to right and top to bottom. Tiles can only slide; you’re not allowed to directly pick them up and rearrange them. Some versions of this puzzle toy feature scram- bled images that form a complete picture once solved. More information about sliding tile puzzles can be found at https:// en.wikipedia.org/wiki/Sliding_puzzle.
You won’t be able to handle the fast-paced excitement of these racing . . . snails. But what they lack in speed they make up for in ASCII-art cuteness. Each snail (represented by an @ character for the shell and v for the two eyestalks) moves slowly but surely toward the finish line. Up to eight snails, each with a custom name, can race each other, leaving a slime trail in their wake. This program is good for beginners.
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An abacus, also called a counting frame, is a calculating tool used in many cultures long before electronic calculators were invented. Figure 70-1 shows the Japanese form of the abacus, called a soroban. Each wire represents a place in a positional numeral system, and the beads on the wire represent the digit at that place. For example, a soroban with two beads moved over on the rightmost wire and three beads moved over on the second-to-rightmost wire would represent the number 32. This program simulates a soroban. (The irony of using a computer to simulate a pre-computer computing tool is not lost on me.)
Each column in the soroban represents a different digit. The rightmost column is the ones place, the column to its left is the tens place, the column to the left of that is the hundreds place, and so on. The Q, W, E, R, T, Y, U, I, O, and P keys along the top of your keyboard can increase the digit at their respective positions, while the A, S, D, F, G, H, J, K, L, and ; keys will decrease them. The beads on the virtual soroban will slide to reflect the current number. You can also enter numbers directly. The four beads below the horizontal divider are “earth” beads, and lift- ing them up against the divider counts as 1 for that digit. The bead above the horizontal divider is a “heaven” bead, and pulling it down against the divider counts as 5 for that digit, so pulling down one heaven bead and pulling up three earth beads in the tens column represents the number 80. More information about abacuses and how to use them can be found at https://en.wikipedia.org/wiki/Abacus.
Similar to the Simon electronic toy, this memorization game uses the third-party playsound module to play four different sounds, which correspond to the A, S, D, and F keys on the keyboard. As you successfully repeat the pattern the game gives you, the patterns get longer and longer. How many sounds can you hold in your short-term memory? If you look at the code, you’ll see that the playsound.playsound() function is passed the filename of the sound to play. You can download the sound files from these URLs: https://inventwithpython.com/soundA.wav https://inventwithpython.com/soundS.wav https://inventwithpython.com/soundD.wav https://inventwithpython.com/soundF.wav
Place these files in the same folder as soundmimic.py before running the program. More information about the playsound module can be found at https://pypi.org/project/playsound/. Users on macOS must also install the pyobjc module from https://pypi.org/project/pyobjc/ for playsound to work.
You’ve probably seen the “Mocking SpongeBob” meme: a picture of SpongeBob SquarePants, with a caption whose text alternates between upper and lowercase letters to indicate sarcasm, like this: uSiNg SpOnGeBoB MeMeS dOeS NoT mAkE YoU wItTy. For some randomness, the text sometimes doesn’t alternate capitalization. This short program uses the upper() and lower() string methods to convert your message into “spongecase.” The program is also set up so that other programs can import it as a module with import spongecase and then call the spongecase.englishToSpongecase() function.
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Sudoku is a popular puzzle game in newspapers and mobile apps. The Sudoku board is a 9 × 9 grid in which the player must place the digits 1 to 9 once, and only once, in each row, column, and 3 × 3 subgrid. The game begins with a few spaces already filled in with digits, called givens. A well-formed Sudoku puzzle will have only one possible valid solution.
This program demonstrates the use of the pyttsx3 third-party module. Any message you enter will be spoken out loud by your operating system’s text-to-speech capabilities. Although computer-generated speech is an incredibly complex branch of computer science, the pyttsx3 module provides an easy interface for it, making this small program suitable for beginners. Once you’ve learned how to use the module, you can add generated speech to your own programs. More information about the pyttsx3 module can be found at https:// pypi.org/project/pyttsx3/.
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Three-card monte is a common scam played on gullible tourists and other easy marks. Three playing cards, one of which is the “red lady” Queen of Hearts, are put facedown on a cardboard box. The dealer quickly rearranges the cards and then asks the mark to pick the Queen of Hearts. But the dealer can use all sorts of tricks to hide the card or otherwise cheat, guaranteeing that the victim never wins. It’s also common for the dealer to have shills in the crowd who secretly work with the dealer but pretend to win the game (to make the victim think they too could win) or purposefully lose badly (to make the victim think they could do much better). This program shows the three cards and then quickly describes a series of swaps. At the end, it clears the screen, and the player must pick a card.
Can you keep up with the “red lady”? For the authentic three-card monte experience, you can enable the cheat feature, which causes the player to always lose, even if they select the correct card.
Tic-tac-toe is a classic pencil-and-paper game played on a 3 × 3 grid. Players take turns placing their X or O marks, trying to get three in a row. Most games of tic-tac-toe end in a tie, but it is possible to outsmart your opponent if they’re not careful.
The Tower of Hanoi is a stack-moving puzzle game that features three poles on which you can stack various-sized disks. The object of the game is to move one tower of disks to another pole. However, only one disk can be moved at a time, and larger disks cannot be placed on top of smaller ones. Figuring out a certain pattern will help you solve this puzzle. Can you discover it? (Hint: Try setting the TOTAL_DISKS variable to 3 or 4 to solve an easier version first.)
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What does a yellow stone thrown into a blue pond become? Do they have a 4th of July in England? How can a doctor go 30 days without sleep? Whatever you think the answers to these trick questions are, you’re probably wrong. The 54 questions in this program have been specifically crafted so that their answers are simple, obvious, and misleading. Finding the true answer will require some cleverness. Copying the code from this book will spoil the fun, since you’ll see the answers, so you might want to download and play this game from https:// inventwithpython.com/trickquestions.py before looking at the source code.
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Gabriele Cirulli, a web developer, invented the game 2048 in one weekend. It was inspired by Veewo Studios’ 1024 game, which in turn was inspired by Threes!, a game by the development team Sirvo. In 2048, you must merge numbers on a 4 × 4 board to clear them from the screen. Two 2s merge into a 4, two 4s merge into an 8, and so on. The game adds a new 2 to the board on each merging. The objective is to reach 2048 before the entire board fills up.
The Vigenère cipher, misattributed to 19th- century cryptographer Blaise de Vigenère (others had independently invented it earlier), was impossible to crack for hundreds of years. It is essentially the Caesar cipher, except it makes use of a multipart key. The so-called Vigenère key is a word, or even a random series of letters. Each letter represents a number by which to shift the letter in the message: A represents shifting a letter in the message by 0, B represents 1, C represents 2, and so on. For example, if a Vigenère key is the word “CAT,” the C represents a shift of 2, the A represents 0, and the T represents 19. The first letter of the message gets shifted by 2, the second letter by 0, and the third letter by 19. For the fourth letter, we repeat the key of 2. This use of multiple Caesar cipher keys is what gives the Vigenère cipher its strength. The possible number of combinations is too big to brute force.
At the same time, the Vigenère cipher doesn’t suffer from the frequency analysis weakness that can crack the simple substitution cipher. For centu- ries, the Vigenère cipher represented the state of the art in cryptography. You’ll notice many similarities between the code for the Vigenère and Caesar cipher programs. More info about the Vigenère cipher can be found at https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher. If you’d like to learn more about ciphers and code breaking, you can read my book Cracking Codes with Python (No Starch Press, 2018; https://nostarch.com/crackingcodes/).
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In this solitaire puzzle game, you must use three buckets (three-liter, five-liter, and eight-liter buckets) to collect exactly four liters of water in one of the buckets. Buckets can only be emptied, completely filled, or poured into another bucket. For example, you can fill the five-liter bucket and then pour its contents into the three-liter bucket, leaving you with a full three-liter bucket and two liters of water in the five-liter bucket. With some effort, you should be able to solve the puzzle. But can you figure out how to solve it with the minimal number of moves?