Remove lint and add VRPy to PyProject.TOML

Signed-off-by: Risbud, Sumedh <sumedh.risbud@intel.com>

pyproject.toml

@@ -58,6 +58,7 @@ scikit-optimize = "^0.9.0"
 scipy = "^1.9.1"
 nbformat = "^5.7.1"
 
+
 [tool.poetry.dev-dependencies]
 bandit = "1.7.4"
 coverage = "^6.3.2"

src/lava/lib/optimization/apps/vrp/solver.py

@@ -7,7 +7,14 @@
 import networkx as ntx
 from pprint import pprint
 from dataclasses import dataclass
-from vrpy import VehicleRoutingProblem
+try:
+    from vrpy import VehicleRoutingProblem
+except ImportError:
+    class VehicleRoutingProblem:
+        def __init__(self, graph):
+            self.graph = graph
+            self.vrpy_not_installed = True
+
 from lava.lib.optimization.problems.problems import QUBO
 from lava.lib.optimization.solvers.generic.solver import OptimizationSolver, \
     SolverReport
@@ -120,7 +127,9 @@ def _prepare_graph_for_vrpy(g):
                     g.add_edge("Source", n, cost=cost_src_to_nod)
                     g.add_edge(n, "Sink", cost=cost_nod_to_snk)
             return g
-        if scfg.core_solver == CoreSolver.VRPY_CPU:
+        vrp = VehicleRoutingProblem(self.problem.problem_graph)
+        vrpy_is_installed = not hasattr(vrp, "vrpy_not_installed")
+        if scfg.core_solver == CoreSolver.VRPY_CPU and vrpy_is_installed:
             # 1. Prepare problem for VRPy
             graph_to_solve = self.problem.problem_graph.copy()
             graph_to_solve = _prepare_graph_for_vrpy(graph_to_solve)
@@ -230,4 +239,5 @@ def _prepare_graph_for_vrpy(g):
                 tsp_routes.update(route)
             return clustering_solution, tsp_routes
         else:
-            raise ValueError("Incorrect core solver specified.")
+            raise ValueError("Incorrect core solver specified or VRPy is not "
+                             "installed.")

src/lava/lib/optimization/solvers/generic/solver.py

@@ -306,7 +306,8 @@ def _get_run_config(
         elif backend in NEUROCORES:
             # from lava.lib.optimization.solvers.generic.read_gate.ncmodels \
             #     import get_read_gate_c_model_class
-            # ReadGateCModel = get_read_gate_c_model_class(num_in_ports, backend)
+            # ReadGateCModel = \
+            # get_read_gate_c_model_class(num_in_ports, backend)
             pdict = {
                 self.solver_process: self.solver_model,
                 ReadGate: ReadGateCModel,