bfs.py

def bfs(graph, start):
    work = {start}
    dist = {} 

    current_dist = 0
    while work:
        for u in work:
            dist[u] = current_dist
        
        work = {nb for u in work 
                   for nb in graph[u]
                   if v not in dist}

dijkstra.py

def dijkstra(graph, start):
    dist = {start: 0}
    border = {u: weight for (u, weight) in graph[start]}

    while border:
        u = min(border, key=lambda u: border[u])
        dist[u] = border[u]
        for (v, weight) in graph[u]:
            if v in dist:
                assert dist[u] + weight >= dist[v]
                continue

            border[v] = min(
                dist[u] + weight,
                border.get(v, float("inf"))
            )