Welcome to PyBnB - 0.7.dev0ΒΆ

pybnb is a parallel branch-and-bound engine written in Python. It designed to run on distributed computing architectures, using mpi4py for fast inter-process communication.

This package is meant to serve as a back-end for problem-specific solution strategies that utilize a branch-and-bound algorithm. The following core functionality is included:

  • work load distribution through a central dispatcher

  • work task prioritization strategies (e.g., worst bound first, breadth first, custom)

  • solver-like log output showing algorithm progress

To use this package, one must implement a branch-and-bound problem by subclassing the Problem interface and defining the methods shown in the example below.

>>> import pybnb
>>> # define a branch-and-bound problem
>>> class MyProblem(pybnb.Problem):
...    def sense(self): ...
...    def objective(self): ...
...    def bound(self): ...
...    def save_state(self, node): ...
...    def load_state(self, node): ...
...    def branch(self): ...
>>> # solve a problem instance
>>> result = pybnb.solve(MyProblem())
>>> print(result.solution_status)