using 'weight' instead of ' cost'

[mindheist]

I guess the original authors might have to take a look to decide this . But In the implementation of Graphs, can we just use "weight" instead of "cost". I suppose most readers would ofcourse understand that its conceptually the same , but I guess it would be more homogenous if the book used 'weight'

    def addEdge(self,f,t,cost=0):
        if f not in self.vertList:
            nv = self.addVertex(f)
        if t not in self.vertList:
            nv = self.addVertex(t)
        self.vertList[f].addNeighbor(self.vertList[t], cost)

    ```

http://interactivepython.org/runestone/static/pythonds/Graphs/Implementation.html