Overview

This library started as a rewrite of DEAP and kept that toolbox model — register operators, run an algorithm. The published API is not a drop-in rename: function names, parameter order, and a few contracts changed, and the surface now includes families DEAP does not ship. Counted from the pages in this section:

• 18 still-open DEAP issues implemented (some older than a decade)
• 84 correctness bugs fixed — operators, GP, CMA, records, checkpoints, published benchmarks, creator, utilities, and algorithms
• 66 capabilities DEAP does not have, including boxed CMA, mixed-gene mutation, logbook JSON, columnar GP, and Push GP

The rest of this section is that inventory: the rewrite itself (this page), then the operators, bookkeeping, genetic programming, quality-diversity archives, and correctness work that accumulated on top of that base. Timed hot paths versus DEAP are on the performance page.

Rewrite and public API

1. The codebase is a complete rewrite for Python 3.12 and newer. The license is Apache-2.0.
2. Algorithms, strategies, and benchmarks live under the tools namespace.
3. All camelCase functions and methods are snake_case.
4. Some functions and methods were renamed entirely.
5. The public surface has type hints.
6. Many parameters were reordered or renamed.
7. Some class properties are now method calls.
8. Hypervolume, hypervolume contributions, and Pareto ranking delegate to moocore (prebuilt C wheels). deap-er stays a pure-Python package. moocore is licensed LGPL-2.1-or-later; do not vendor its sources into this tree.
9. 3.0 breaking changes: sort_log_non_dominated and the HyperVolume class are removed. sort_non_dominated no longer takes ffo. sel_nsga_2 / sel_nsga_3 no longer take sorting. least_contrib no longer takes map_func. StrategyMultiObjective no longer takes mp_pool.
10. State persistence is implemented with the Checkpoint class.
11. Deprecated and obsolete DEAP APIs are removed.
12. The documentation matches the current API.