如何从函数返回字典？

Question

I have a small piece of code :

def extract_nodes():
    for i in json.load(open('/home/ubuntu/slcakbot_openNMS/CLEAR/out.txt'))["node"]:
        try:
          socket.inet_aton(i["label"])
          print(i["label"])
          print(i["id"])
          #return { 'ip': i["label"], 'id': i["id"]}  #  i need to return these values

        except Exception as e:
          pass

I need to create a dict and return it to the calling function, i am not sure how do i create a dict and return from here. Also once returned how do i use the dictionary value

Answer 1

There may be more than one values for the key "id" and "label",so you should consider use list . Here is my code

def extract_nodes():
    labels = []
    ids = []
    results = {}
    for i in json.load(open('/home/ubuntu/slcakbot_openNMS/CLEAR/out.txt'))["node"]:
        try:
          socket.inet_aton(i["label"])
          print(i["label"])
          labels.append(i["label"])
          print(i["id"])
          ids.append(i["id"])
          #return { 'ip': i["label"], 'id': i["id"]}  #  i need to return these values

        except Exception as e:
          pass
    results['ip']=labels
    results['id']=ids
    return results

I hope it can work :)

Answer 2

You could use a generator, but I'm guessing you are new to python and this will be simpler:

def extract_nodes():
    return_data = dict()
    for node_datum in json.load(open('/home/ubuntu/slcakbot_openNMS/CLEAR/out.txt'))["node"]:
        try:
          socket.inet_aton(node_datum["label"])
          return_data[node_datum["id"]] = { 'ip': node_datum["label"], 'id': node_datum["id"]}
          print(node_datum["label"])
          print(node_datum["id"])
          #return { 'ip': node_datum["label"], 'id': node_datum["id"]}  #  i need to return these values

        except Exception as err:
            print err
            pass

    return return_data

As for using it,

node_data = extract_nodes()
for key, node_details in node_data.items():
    print node_details['ip'], node_details['id']

Answer 3

def extract_nodes():
    to_return_dict = dict()
    for i in json.load(open('/home/ubuntu/slcakbot_openNMS/CLEAR/out.txt'))["node"]:
        try:
          socket.inet_aton(i["label"])
          to_return_dict[i['id']] = i['label']
          print(i["label"])
          print(i["id"])
          #return { 'ip': i["label"], 'id': i["id"]}  #  i need to return these values

        except Exception as e:
          pass
   return to_return_dict 

This should do it.... Let me know if it works!

Edit:

As for how to use it:

id_label_dict = extract_nodes()
print(id_label_dict['ip']) # should print the label associated with 'ip'