Installation

This branch’s native JuMP/GenOpt integration is a prototype. Both building the compiled backend and using JuliaCall currently require the patched development checkout of GenOpt; released GenOpt 0.2.3 lacks the required lazy-sum bridge. Building the compiled backend also requires the concrete-model JuMP development patch. Follow the development environment setup to select that checkout without changing the repository manifest.

Install JuMPy from PyPI:

pip install jumpy

Select the compiled HiGHS interface explicitly:

import jumpy.highs as jp

model = jp.Model()

It uses the compiled backend shipped with JuMPy and requires neither a Julia installation nor juliacall.

JuliaCall interface

pip install 'jumpy[juliacall]'

import jumpy.juliacall as jp

model = jp.Model()  # A JuMP model without a solver

Install and load a solver in the JuliaCall environment explicitly. For example, with HiGHS:

from juliacall import Main as jl

jl.seval('using Pkg; Pkg.add("HiGHS"); import HiGHS')
model = jp.Model(jl.HiGHS.Optimizer)

This forwards the optimizer factory to JuMP.Model. To use an existing optimizer instance with JuMP’s direct mode:

model = jp.direct_model(jl.HiGHS.Optimizer())

This interface loads Julia and uses the same native JuMP/GenOpt expression operations as the compiled backend. JuliaCall’s Model uses normal JuMP caching and GenOpt bridges. Its direct_model uses the optimizer without added layers. Compiled HiGHS uses a concrete direct model over raw MOI, without bridges. jp.MOI is Julia’s actual MathOptInterface module. It does not need the compiled JuMPy library. Both interfaces expose the same modeling helpers and jp.MOI, but they are alternatives: choose one per Python process, and do not pass models, expressions, or sets between them.

Model() takes no backend argument; the import selects it. The root package no longer exports jumpy.Model.

Development documentation

The executable tutorials require a locally built JuMPy library. Follow the compiled backend build instructions, then build the documentation with:

uv run --group docs sphinx-build -M html docs/source docs/build -W --keep-going

Set JUMPY_LIB to the compiled library if it is not in the default development location.

The tutorials import jumpy.highs and do not require JuliaCall.