distance.py

def distanceBetween(self, cities=[]):
        
        """
        Calculates distance of the route
        Args:
            cities (str[]): The array of cities

        Returns:
            int: calclated distance
        """

        distance = 0 
        '''
        for every cities we will be looking at the adjacent route and 
        adding the weight of route to total distance
        '''
        for i in range(len(cities)):
            root_node = cities[i]
            if i + 1 < len(cities):
                next_node = cities[i+1]
                if next_node in self.routesTable[root_node]:
                    distance = distance + self.routesTable[root_node][next_node]
                else: 
                    return "There is no route"
        return distance