NetworkX KeyError on some datasets while calling prob.solve()

[sumi1234]

The library is great and very easy to use ! While implementing on my own data, I am facing the following error :

Context : This error only occurs when certain delivery locations are added to my input data. What is the root cause of such errors and how can I clean/mitigate the same ? It seems to be a NetworkX specific issue.

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-13-d9e2204baef3> in <module>
      1 from vrpy import VehicleRoutingProblem
      2 prob = VehicleRoutingProblem(G, load_capacity=4)
----> 3 prob.solve()

~\anaconda3\lib\site-packages\vrpy\main.py in solve(self, initial_routes, preassignments, pricing_strategy, cspy, exact, time_limit, solver, dive, greedy)
    176 
    177         # Initialization
--> 178         self._initialize()
    179 
    180         # Column generation

~\anaconda3\lib\site-packages\vrpy\main.py in _initialize(self)
    263         else:
    264             # Initial solution is computed with Clarke & Wright (or round trips)
--> 265             self._get_initial_solution()
    266         # Initial routes are converted to digraphs
    267         self._convert_initial_routes_to_digraphs()

~\anaconda3\lib\site-packages\vrpy\main.py in _get_initial_solution(self)
    469                 self.G, self.load_capacity, self.duration, self.num_stops
    470             )
--> 471             alg.run()
    472             logger.info("Initial solution found with value %s" % alg.best_value)
    473             self._initial_routes = alg.best_routes

~\anaconda3\lib\site-packages\vrpy\clarke_wright.py in run(self)
     31     def run(self):
     32         """Runs Clark & Wrights savings algorithm."""
---> 33         self._initialize_routes()
     34         self._get_savings()
     35         for (i, j) in self._ordered_edges:

~\anaconda3\lib\site-packages\vrpy\clarke_wright.py in _initialize_routes(self)
     43                 # Create round trip
     44                 round_trip_cost = (
---> 45                     self.G.edges["Source", v]["cost"] + self.G.edges[v, "Sink"]["cost"]
     46                 )
     47                 route = DiGraph(cost=round_trip_cost)

~\anaconda3\lib\site-packages\networkx\classes\reportviews.py in __getitem__(self, e)
    928     def __getitem__(self, e):
    929         u, v = e
--> 930         return self._adjdict[u][v]
    931 
    932     # EdgeDataView methods

KeyError: 29

Any help would be much appreciated !!

[Kuifje02]

An error is raised because there seems to be missing edges: at least one node is not connected to the Source and/or Sink. To start with, can you verify this ?

[sumi1234]

I checked and it seemed to be an issue specific to the data I am using. All nodes are connected but there is some corrupted data in the data file I am using and removing that row stops the error from happening.

I will get back once I do a more thorough deep-dive on my own raw data. You can mark the issue as closed until then.