I am trying to implement Dijkstra without writing lot of code for the Graph class itself. I have implemented it from Wikipedia. However, I am not fond of the way I have handled the minimum distance calculation. I would like to have some improvement on that.

graph = {'s': {'v':1,'w':4 },          'v': {'w':2,'t':6},          'w': {'t':3},          't': {'': None}          } def dj(graph, start):     Q = []# queue to hold all the vertices     dist = {} #dictionary to hold all the distance     prev = {} #dictionary to hold all the previous node visited      for key in graph.keys():         dist[key] = 1000         prev[key] = ""         Q.append(key)       dist[start] = 0      #I had to have another distance data structure dst     # to store all the distance covered     # I am not fond of it     dst = []      while Q:         # Here I get the minimum distance         u = min(dist, key = dist.get)         # remove the min one from Q         Q.remove(u)         for v in graph[u]:             #I also want to improvise this condition block             #It is because of 't': {'': None}              if graph[u][v] is None:                 continue             alt = dist[u] + graph[u][v]             if alt < dist[v]:                 dist[v] = alt                 prev[v] = u         #I have to discard the minimum key from dist dictionary         d = (dist.pop(u))         # I then have to append the discarded one to dst dictionary         # Redundant work         dst.append(d)      return dst,prev  print(dj(graph,'s'))