Function pick_default_solver

cvxpy/problems/problem_form.py:336–387

Pick the default solver for a problem based on its structure. Checks commercial solvers first when configured to do so, then falls back to open-source defaults based on problem type. Parameters ---------- problem_form : ProblemForm Pre-canonicalization structural analys

(problem_form: ProblemForm)

def pick_default_solver(problem_form: ProblemForm) -> Solver | None:
    """Pick the default solver for a problem based on its structure.

    Checks commercial solvers first when configured to do so, then falls
    back to open-source defaults based on problem type.

    Parameters
    ----------
    problem_form : ProblemForm
        Pre-canonicalization structural analysis of the problem.

    Returns
    -------
    Solver or None
        A solver instance, or None if no suitable installed solver is found.
    """
    def _get(solver_map, name):
        inst = solver_map.get(name)
        return inst if inst is not None and inst.is_installed() else None

    if s.DEFAULT_TO_COMMERCIAL_SOLVERS:
        for solver_name in slv_def.COMMERCIAL_SOLVERS:
            solver = _get(slv_def.SOLVER_MAP_CONIC, solver_name)
            if solver is not None and solver.can_solve(problem_form):
                return solver

    # Mixed-integer: LP → HIGHS, non-LP → SCIP.
    if problem_form.is_mixed_integer():
        if problem_form.is_lp():
            solver = _get(slv_def.SOLVER_MAP_CONIC, s.HIGHS)
            if solver is not None:
                return solver
        solver = _get(slv_def.SOLVER_MAP_CONIC, s.SCIP)
        if solver is not None and solver.can_solve(problem_form):
            return solver
        return None

    # LP → Clarabel.
    if problem_form.cones() <= _QP_CONES:
        return _get(slv_def.SOLVER_MAP_CONIC, s.CLARABEL)

    # QP → OSQP.
    if problem_form.has_quadratic_objective() \
            and problem_form.cones(quad_obj=True) <= _QP_CONES:
        return _get(slv_def.SOLVER_MAP_QP, s.OSQP)

    # SDP → SCS.
    if PSD in problem_form.cones():
        return _get(slv_def.SOLVER_MAP_CONIC, s.SCS)

    # Everything else (SOCP, ExpCone, PowCone, etc.) → Clarabel.
    return _get(slv_def.SOLVER_MAP_CONIC, s.CLARABEL)


def make_problem_form(problem: Problem, gp: bool, ignore_dpp: bool) -> ProblemForm: