shortestPath.py

    def findShortestRoute(self, start, end , weight, shortestRoute, visited=[]):
        """
        Recursive function to calculate the shortest route
        Args:
            start           (str):      Starting city
            end             (str):      Destination city
            weight          (weight):   weight of the route
            shortestRoute   (int):      shortest path so far
            visited         (str[]):    array of visited nodes

        Returns:
            int: calclated weight of the shortest route
        """

        # Check if start and end nodes exists in route table
        if start in self.routesTable and end in self.routesTable:
            visited.append(start) # mark start to visited

            for adj in self.routesTable[start]:
                if(adj == end or adj not in visited):
                    weight += self.routesTable[start][adj]
                    
                '''
                If destination matches, we compare
                weight of this route to shortest route
                so far, and make appropriate switch
                '''

                if adj == end:
                    if shortestRoute == 0 or weight < shortestRoute:
                        shortestRoute = weight
                    visited.remove(start)
                    return shortestRoute
                '''
                If destination does not match, and
				destination node has not yet been visited,
				we recursively traverse destination node
                '''
                if adj not in visited:
                    shortestRoute = self.findShortestRoute(adj, end, weight, shortestRoute, visited)
                    weight -= self.routesTable[start][adj]
        
        else:
            return "No such route exists"

        if start in visited:
            visited.remove(start)
        
        return shortestRoute