#633 added test for klu and skip if KLU not installed

pybamm/__init__.py

@@ -237,7 +237,7 @@ def version(formatted=False):
 from .solvers.scikits_ode_solver import ScikitsOdeSolver
 from .solvers.scikits_ode_solver import have_scikits_odes
 from .solvers.algebraic_solver import AlgebraicSolver
-from .solvers.klu_sparse_solver import KLU
+from .solvers.klu_sparse_solver import KLU, have_klu
 
 
 #

pybamm/solvers/klu_sparse_solver.py

@@ -2,12 +2,20 @@
 # Solver class using sundials with the KLU sparse linear solver
 #
 import pybamm
-
 import numpy as np
-
-import klu
 import scipy.sparse as sparse
 
+import importlib
+
+klu_spec = importlib.util.find_spec("klu")
+if klu_spec is not None:
+    klu = importlib.util.module_from_spec(klu_spec)
+    klu_spec.loader.exec_module(klu)
+
+
+def have_klu():
+    return klu_spec is None
+
 
 class KLU(pybamm.DaeSolver):
     """Solve a discretised model, using sundials with the KLU sparse linear solver.
@@ -31,6 +39,8 @@ class KLU(pybamm.DaeSolver):
     def __init__(
         self, method="ida", tol=1e-8, root_method="lm", root_tol=1e-6, max_steps=1000
     ):
+        if klu_spec is None:
+            raise ImportError("KLU is not installed")
 
         super().__init__(method, tol, root_method, root_tol, max_steps)
 

pybamm/solvers/scikits_ode_solver.py

@@ -134,7 +134,7 @@ def jac_times_setupfn(t, y, fy, userdata):
                 np.transpose(sol.values.y),
                 sol.roots.t,
                 np.transpose(sol.roots.y),
-                termination
+                termination,
             )
         else:
             raise pybamm.SolverError(sol.message)