connections = [('Würzburg', 'Schweinfurt', 50),
             ('Würzburg', 'Nürnberg', 100),
             ('Schweinfurt', 'Bamberg', 60),
             ('Bamberg', 'Coburg', 50),
             ('Bamberg', 'Nürnberg', 60),
             ('Bamberg', 'Bayreuth', 60),
             ('Nürnberg', 'Bayreuth', 90),
             ('Bayreuth', 'Hof', 50),
             ('Coburg', 'Hof', 80),
            ]

def allNodes(connections):
    nodes = set()

    for a in connections:
        nodes.add(a[0])
        nodes.add(a[1])
    
    return nodes

def initMap(connections):

    m = allNodes(connections)
    knoten = {}
    
    for a in m:
        knoten[a] = {}
    
    return knoten

def addConnection(data, connection):
    a, b, c = connection

    data[a].setdefault('connection', []).append([b, c])
    data[b].setdefault('connection', []).append([a, c])

    return data



    
map = initMap(connections)
print(initMap(connections))
print(connections[0][0])
for con in connections:
    addConnection(map, con)
print(map)