Motivation

This project started its life as a coding challenge I was asked to solve while interviewing in 2015 for a software engineering position at Uber.

After the interview proccess ended, I kept toying with the code, as a playground to test some optimization strategies in Python. It is now a boilerplate that I use to:

• bootstrap CLI-based projects powered with Click,

• keep up with the current state-of-art of Python packaging,

• streamline the integration of a data stack (Numpy, Pandas, Seaborn and Conda),

• automate testing and quality checks (unit-tests, coverage, coding style and packaging),

• provide an auto-generated documentation.

Examples

Simple 3x3 board with 2 kings and a rook:

$ chessboard solve --length=3 --height=3 --king=2 --rook=1
<SolverContext: length=3, height=3, pieces={'rook': 1, 'king': 2, 'queen': 0, 'bishop': 0, 'knight': 0}>
Searching positions...
┌───┬───┬───┐
│ ♚ │   │   │
├───┼───┼───┤
│   │   │ ♜ │
├───┼───┼───┤
│ ♚ │   │   │
└───┴───┴───┘
┌───┬───┬───┐
│   │   │ ♚ │
├───┼───┼───┤
│ ♜ │   │   │
├───┼───┼───┤
│   │   │ ♚ │
└───┴───┴───┘
┌───┬───┬───┐
│ ♚ │   │ ♚ │
├───┼───┼───┤
│   │   │   │
├───┼───┼───┤
│   │ ♜ │   │
└───┴───┴───┘
┌───┬───┬───┐
│   │ ♜ │   │
├───┼───┼───┤
│   │   │   │
├───┼───┼───┤
│ ♚ │   │ ♚ │
└───┴───┴───┘
4 results found in 0.03 seconds.

Famous eight queens puzzle, without printing the solutions to speed things up:

$ chessboard solve --length=8 --height=8 --queen=8 --silent
<SolverContext: length=8, height=8, pieces={'rook': 0, 'king': 0, 'queen': 8, 'bishop': 0, 'knight': 0}>
Searching positions...
92 results found in 119.87 seconds.

Huge combinatoric problem can take some time to solve:

$ chessboard solve --length=7 --height=7 --king=2 --queen=2 --bishop=2 --knight=1 --silent
<SolverContext: length=7, height=7, pieces={'rook': 0, 'king': 2, 'queen': 2, 'bishop': 2, 'knight': 1}>
Searching positions...
3063828 results found in 9328.33 seconds.

The CLI allow the production of a profiling graph, to identify code hot spots and bottleneck:.

$ chessboard solve --length=6 --height=6 --king=2 --queen=2 --bishop=2 --knight=1 --silent --profile
<SolverContext: length=6, height=6, pieces={'rook': 0, 'king': 2, 'queen': 2, 'bishop': 2, 'knight': 1}>
Searching positions...
23752 results found in 207.25 seconds.
Execution profile saved at /home/kevin/chessboard/solver-profile.png

Third-party

This project package’s boilerplate is sourced from the code I wrote for Scaleway’s postal-address module, which is published under a GPLv2+ License.

The CLI code is based on the one I wrote for the kdenlive-tools module, published under a BSD license.

Other resources

• Awesome Chess: curated list of assets

• Combinatorial Generation

• Applied Combinatorics

• Extremal Problems

• Combinatorial Algorithms

Changes for v1.5.4 (2017-08-11)

• Show selected log level in debug mode.

• Drop support and unittests on Mac OS X 10.9.

• Add new macOS 10.12 target for Travis CI builds.

• Bump requirement to readme_renderer >= 16.0.

• Move installation instructions to documentation.

• Move performance page to documentation.

• Move CLI usage to own section in docs.

• Activate unittests in Python 3.6.

• Show environment variables in Travis jobs for debugging.

• Check there is no conflicting dependencies in Travis jobs.

• Show the graph of package dependencies in documentation.

• Fix upgrade of setuptools in macOS + Python 3.3 Travis jobs.

Full changelog.