# pytudes

*Etudes* are exercises to practice or demonstrate skills, long used by piano players. 

This project contains **pytudes**—Python programs to practice or demonstrate skills.
 
# pytudes: Index of Jupyter (IPython) Notebooks

|Logic and Number Puzzles|
|---|
|[Advent of Code 2016](https://github.com/norvig/pytudes/blob/master/Advent%20of%20Code.ipynb)<br>*Puzzle site with a coding puzzle each day for Advent 2016*|
|[Translating English Sentences into Propositional Logic Statements](https://github.com/norvig/pytudes/blob/master/PropositionalLogic.ipynb)<br>*Automatically converting informal English sentences into formal Propositional Logic.*|
|[The Puzzle of the Misanthropic Neighbors](https://github.com/norvig/pytudes/blob/master/Mean%20Misanthrope%20Density.ipynb)<br>*How crowded will this neighborhood be, if nobody wants to live next door to anyone else?*|
|[Countdown to 2016](https://github.com/norvig/pytudes/blob/master/Countdown.ipynb)<br>*Solving the equation 10 _ 9 _ 8 _ 7 _ 6 _ 5 _ 4 _ 3 _ 2 _ 1 = 2016. From an Alex Bellos puzzle.*|
|[Sicherman Dice](https://github.com/norvig/pytudes/blob/master/Sicherman%20Dice.ipynb)<br>*Find a pair of dice that is like a regular pair of dice, only different.*|
|[Beal's Conjecture Revisited](https://github.com/norvig/pytudes/blob/master/Beal.ipynb)<br>*A search for counterexamples to Beal's Conjecture*|
|[When is Cheryl's Birthday?](https://github.com/norvig/pytudes/blob/master/Cheryl.ipynb)<br>*Solving the "Cheryl's Birthday" logic puzzle.*|
|[When Cheryl Met Eve: A Birthday Story](https://github.com/norvig/pytudes/blob/master/Cheryl-and-Eve.ipynb)<br>*Inventing new puzzles in the Style of Cheryl's Birthday.*|
|[Sol Golomb's Rectangle Puzzle](https://github.com/norvig/pytudes/blob/master/Golomb-Puzzle.ipynb)<br>*A Puzzle involving placing rectangles of different sizes inside a square. Bonus: cryptarithmetic.*|
|[WWW: Will Warriors Win?](https://github.com/norvig/pytudes/blob/master/WWW.ipynb)<br>*Golden State Warriors probability of winning the 2016 NBA title.*|

|Word Games|
|---|
|[Ghost](https://github.com/norvig/pytudes/blob/master/Ghost.ipynb)<br>*The word game Ghost (add letters, try to avoid making a word).*|
|[World's Longest Palindrome](https://github.com/norvig/pytudes/blob/master/pal3.ipynb)<br>*Searching for a long Panama-style palindrome, this time letter-by-letter.*|
|[Refactoring a Crossword Game Program](https://github.com/norvig/pytudes/blob/master/Scrabble.ipynb)<br>*Refactoring the Scrabble / Word with Friends game from Udacity 212.*|
|[xkcd 1313: Regex Golf](https://github.com/norvig/pytudes/blob/master/xkcd1313.ipynb)<br>*Find the smallest regular expression; inspired by Randall Monroe.*|
|[xkcd 1313: Regex Golf (Part 2: Infinite Problems)](https://github.com/norvig/pytudes/blob/master/xkcd1313-part2.ipynb)<br>*Regex Golf: better, faster, funer. With Stefan Pochmann.*|
|[Let's Code About Bike Locks](https://github.com/norvig/pytudes/blob/master/Fred%20Buns.ipynb)<br>*A tale of a bicycle combination lock that uses letters instead of digits. Inspired by Bike Snob NYC.*|
|[Gesture Typing](https://github.com/norvig/pytudes/blob/master/Gesture%20Typing.ipynb)<br>*What word has the longest path on a gesture-typing smartphone keyboard? Inspired by Nicolas Schank and Shumin Zhai.*|
|[How to Do Things with Words, or Statistical Natural Language Processing in Python](https://github.com/norvig/pytudes/blob/master/How%20to%20Do%20Things%20with%20Words.ipynb)<br>*Spelling Correction, Secret Codes, Word Segmentation, and more: grab your bag of words.*|

|Computer Science Algorithms, Concepts, and Problems|
|---|
|[A Chaos Game with Triangles](https://github.com/norvig/pytudes/blob/master/Sierpinski.ipynb)<br>*A surprising appearance of the Sierpinski triangle in a random walk between vertexes.*|
|[BASIC Interpreter](https://github.com/norvig/pytudes/blob/master/BASIC.ipynb)<br>*How to write an interpreter for the BASIC programming language.*|
|[Conway's Game of Life](https://github.com/norvig/pytudes/blob/master/Life.ipynb)<br>*The cellular automata zero-player game.*|
|[A Concrete Introduction to Probability](https://github.com/norvig/pytudes/blob/master/Probability.ipynb)<br>*Code and examples of the basic principles of Probability Theory.*|
|[Probability, Paradox, and the Reasonable Person Principle](https://github.com/norvig/pytudes/blob/master/ProbabilityParadox.ipynb)<br>*Some classic paradoxes in Probability Theory, and how too think about disagreements.*|
|[The Convex Hull Problem](https://github.com/norvig/pytudes/blob/master/Convex%20Hull.ipynb)<br>*A classic Computer Science Algorithm.*|
|[The Traveling Salesperson Problem](https://github.com/norvig/pytudes/blob/master/TSP.ipynb)<br>*Another of the classics.*|
|[Economics Simulation](https://github.com/norvig/pytudes/blob/master/Economics.ipynb)<br>*A simulation of a simple economic game.*|
|[Project Euler Utilities](https://github.com/norvig/pytudes/blob/master/Project%20Euler%20Utils.ipynb)<br>*My utility functions for the Project Euler problems, including `Primes` and `Factors`.*|

# pytudes: Index of Python Files

The following are not notebooks, but raw `.py` files, although some of them have separate `.html` files as documentation.


| **File** | **Description** | **Documentation**|
|:--------|:-------------------|----|
|[SET.py](https://github.com/norvig/pytudes/blob/master/SET.py)|Analyze the card game [SET](http://www.setgame.com/set).|[SET.html](http://norvig.com/SET.html)|
|[beal.py](https://github.com/norvig/pytudes/blob/master/beal.py)|Search for counterexamples to Beal's Conjecture|[beal.html](http://norvig.com/beal.html)
|[docex.py](https://github.com/norvig/pytudes/blob/master/docex.py)|A framework for running unit tests, similar to `doctest`.|
|[ibol.py](https://github.com/norvig/pytudes/blob/master/ibol.py)|An Exercise in Species Barcoding|[ibol.html](http://norvig.com/ibol.html)
|[lettercount.py](https://github.com/norvig/pytudes/blob/master/lettercount.py)|Convert Google Ngram Counts to Letter Counts|[mayzner.html](http://norvig.com/mayzner.html)
|[lis.py](https://github.com/norvig/pytudes/blob/master/lis.py)|Lisp Interpreter written in Python|[lispy.html](http://norvig.com/lispy.html)
|[lispy.py](https://github.com/norvig/pytudes/blob/master/lispy.py)|Even Better Lisp Interpreter written in Python|[lispy2.html](http://norvig.com/lispy2.html)
|[lispytest.py](https://github.com/norvig/pytudes/blob/master/lispytest.py)|Tests for Lisp Interpreters|
|[pal.py](https://github.com/norvig/pytudes/blob/master/pal.py)|Find long palindromes|[palindrome.html](http://norvig.com/palindrome.html)
|[pal2.py](https://github.com/norvig/pytudes/blob/master/pal2.py)|Find longer palindromes|[palindrome.html](http://norvig.com/palindrome.html)
|[pal3.py](https://github.com/norvig/pytudes/blob/master/pal3.py)|Find even longer palindromes|[palindrome.html](http://norvig.com/palindrome.html)
|[py2html.py](https://github.com/norvig/pytudes/blob/master/py2html.py)|Pretty-printer to format Python files as html|
|[spell.py](https://github.com/norvig/pytudes/blob/master/spell.py)|Spelling corrector|[spell-correct.html](http://norvig.com/spell-correct.html)
|[sudoku.py](https://github.com/norvig/pytudes/blob/master/sudoku.py)|Program to solve sudoku puzzles|[sudoku.html](http://norvig.com/sudoku.html)
|[testaccum.py](https://github.com/norvig/pytudes/blob/master/testaccum.py)|Tests for my failed Python `accumulation display` proposal|[pyacc.html](http://norvig.com/pyacc.html)
|[yaptu.py](https://github.com/norvig/pytudes/blob/master/yaptu.py)|Yet Another Python Templating Utility|