README.md -- moved parts to CONTRIBUTING.md

Author: norvig

README.md

@@ -1,7 +1,7 @@
 # ![](https://github.com/aimacode/aima-java/blob/gh-pages/aima3e/images/aima3e.jpg)`aima-python`[![Build Status](https://travis-ci.org/aimacode/aima-python.svg?branch=master)](https://travis-ci.org/aimacode/aima-python)
 
 
-Python code for the book *Artificial Intelligence: A Modern Approach.* We're loooking for one student sponsored by Google Summer of Code ([GSoC](https://summerofcode.withgoogle.com/)) to work on this project; if you want to be that student, make some good contributions here (by looking through the [Issues](https://github.com/aimacode/aima-python/issues) and resolving some), and submit an [application](https://summerofcode.withgoogle.com/terms/student). (However, be warned that we've had over 150 students express interest, so competition will be tough.) And we're always looking for solid contributors who are not affiliated with GSoC. A big thank you to everyone who has contributed!
+Python code for the book *Artificial Intelligence: A Modern Approach.* We're loooking for one student sponsored by Google Summer of Code ([GSoC](https://summerofcode.withgoogle.com/)) to work on this project; if you want to be that student, make some good [contributions](https://github.com/aimacode/aima-python/blob/master/CONTRIBUTING.md) here by looking through the [Issues](https://github.com/aimacode/aima-python/issues) and resolving some), and submit an [application](https://summerofcode.withgoogle.com/terms/student). (However, be warned that we've had over 150 students express interest, so competition will be tough.) And we're always [looking for solid contributors](https://github.com/aimacode/aima-python/blob/master/CONTRIBUTING.md) who are not affiliated with GSoC. A big thank you to everyone who has contributed!
 
 ## Python 3.4
 
@@ -17,11 +17,6 @@ When complete, this project will have Python code for all the pseudocode algorit
 
 Until we get there, we will support a legacy branch, `aima3python2` (for the third edition of the textbook and for Python 2 code). To prepare code for the new master branch, the following two steps should be taken:
 
-## Port to Python 3; Pythonic Idioms; py.test
-
-- Check for common problems in [porting to Python 3](http://python3porting.com/problems.html), such as: `print` is now a function; `range` and `map` and other functions no longer produce `list`s; objects of different types can no longer be compared with `<`; strings are now Unicode; it would be nice to move `%` string formating to `.format`; there is a new `next` function for generators; integer division now returns a float; we can now use set literals.
-- Replace old Lisp-based idioms with proper Python idioms. For example, we have many functions that were taken directly from Common Lisp, such as the `every` function: `every(callable, items)` returns true if every element of `items` is callable. This is good Lisp style, but good Python style would be to use `all` and a generator expression: `all(callable(f) for f in items)`. Eventually, fix all calls to these legacy Lisp functions and then remove the functions.
-- Add more tests in `_test.py` files. Strive for terseness; it is ok to group multiple asserts into one `def test_something():` function. Move most tests to `_test.py`, but it is fine to have a single `doctest` example in the docstring of a function in the `.py` file, if the purpose of the doctest is to explain how to use the function, rather than test the implementation.
 
 ## New and Improved Algorithms
 
@@ -30,23 +25,6 @@ Until we get there, we will support a legacy branch, `aima3python2` (for the thi
 We hope to have a `algorithm-name.md` file for each algorithm, eventually; it would be great if contributors could add some for the existing algorithms.
 - Give examples of how to use the code in the `.ipynb` file.
 
-# Style Guide
-
-There are a few style rules that are unique to this project:
-
-- The first rule is that the code should correspond directly to the pseudocode in the book. When possible this will be almost one-to-one, just allowing for the syntactic differences between Python and pseudocode, and for different library functions.
-- Don't make a function more complicated than the pseudocode in the book, even if the complication would add a nice feature, or give an efficiency gain. Instead, remain faithful to the pseudocode, and if you must, add a new function (not in the book) with the added feature.
-- I use functional programming (functions with no side effects) in many cases, but not exclusively (sometimes classes and/or functions with side effects are used). Let the book's pseudocode be the guide.
-
-Beyond the above rules, we use [Pep 8](https://www.python.org/dev/peps/pep-0008), with a few minor exceptions:
-
-- I have set `--max-line-length 100`, not 79.
-- You don't need two spaces after a sentence-ending period.
-- Strunk and White is [not a good guide for English](http://chronicle.com/article/50-Years-of-Stupid-Grammar/25497).
-- I prefer more concise docstrings; I don't follow [Pep 257](https://www.python.org/dev/peps/pep-0257/).
-- Not all constants have to be UPPERCASE.
-- At some point I may add [Pep 484](https://www.python.org/dev/peps/pep-0484/) type annotations, but I think I'll hold off for now;
-  I want to get more experience with them, and some people may still be in Python 3.4.
 
 # Index of Code #
 
@@ -147,28 +125,6 @@ Here is a table of algorithms, the figure and page where they appear in the book
 | 23.1    | 837      | Viterbi-Segmentation | `viterbi_segment` | [`text.py`](../master/text.py) |
 | 24.21   | 892      | Align              |          |
 
-# Choice of Programming Languages
-
-Are we right to concentrate on Java and Python versions of the code? I think so; both languages are popular; Java is
-fast enough for our purposes, and has reasonable type declarations (but can be verbose); Python is popular and has a very direct mapping to the pseudocode in the book (but lacks type declarations and can be slow). The [TIOBE Index](http://www.tiobe.com/tiobe_index) says the top five most popular languages are:
-
-        Java, C, C++, C#, Python
-
-So it might be reasonable to also support C++/C# at some point in the future. It might also be reasonable to support a language that combines the terse readability of Python with the type safety and speed of Java; perhaps Go or Julia. And finally, Javascript is the language of the browser; it would be nice to have code that runs in the browser, in Javascript or a variant such as Typescript.
-
-There is also a `aima-lisp` project; in 1995 when we wrote the first edition of the book, Lisp was the right choice, but today it is less popular.
-
-What languages are instructors recommending for their AI class? To get an approximate idea, I gave the query <tt>[norvig russell "Modern Approach"](https://www.google.com/webhp#q=russell%20norvig%20%22modern%20approach%22%20java)</tt> along with the names of various languages and looked at the estimated counts of results on
-various dates. However, I don't have much confidence in these figures...
-
-|Language  |2004  |2005  |2007  |2010  |2016  |
-|--------  |----: |----: |----: |----: |----: |
-|[none](http://www.google.com/search?q=norvig+russell+%22Modern+Approach%22)|8,080|20,100|75,200|150,000|132,000|
-|[java](http://www.google.com/search?q=java+norvig+russell+%22Modern+Approach%22)|1,990|4,930|44,200|37,000|50,000|
-|[c++](http://www.google.com/search?q=c%2B%2B+norvig+russell+%22Modern+Approach%22)|875|1,820|35,300|105,000|35,000|
-|[lisp](http://www.google.com/search?q=lisp+norvig+russell+%22Modern+Approach%22)|844|974|30,100|19,000|14,000|
-|[prolog](http://www.google.com/search?q=prolog+norvig+russell+%22Modern+Approach%22)|789|2,010|23,200|17,000|16,000|
-|[python](http://www.google.com/search?q=python+norvig+russell+%22Modern+Approach%22)|785|1,240|18,400|11,000|12,000|
 
 # Acknowledgements