for data in json_dictionary: # Loop through dictionary keys NameError: name 'json_dictionary' is not defined

Question

def on_message(client, userdata, msg):  # The callback for when a message is received from the server.      
    json_string = str(msg.payload)
    json_dictionary = json.loads(json_string)  # Load JSON string to a dictionary


for data in json_dictionary:  # Loop through dictionary keys
    print(data, ":", json_dictionary[data])

Answer 1

It gives an error as json_dictionary is inside the function. You need to either return or declare json_dictioanry and then call the function on_message. Try in this way:

def on_message(client, userdata, msg):  # The callback for when a message is received from the server.
    json_string = str(msg.payload)
    json_dictionary = json.loads(json_string)  # Load JSON string to a dictionary
    return json_dictionary

json_dictionary = on_message(client,userdata,msg)
for data in json_dictionary.keys():
    print(data, ":", json_dictionary[data])