See real time changes in data using python meteor

Question

I am using Python to retrieve data from Mongo database to analyze it. So I am changing data using meteor app and client python to retrieve it in a real time. This is my code:

from MeteorClient import MeteorClient
def call_back_meth():
    print("subscribed")
client = MeteorClient('ws://localhost:3000/websocket')
client.connect()
client.subscribe('tasks', [], call_back_meth)
a=client.find('tasks')
print(a)

when I run this script, it only show me current data in 'a' and console will close,

I want to let the console stay open and print data in case of change. I have used While True to let script running and see changes but I guess it's not a good solution. Is there any another optimized solution?

I've never used MeteorClient in Python, but in Meteor there is an [observer function](http://docs.meteor.com/api/collections.html#Mongo-Cursor-observe) you can call on a cursor and it will run a callback each time data is added/updated/deleted from the collection. See if you can find the equivalent function in MeteorClient. — jordanwillis, Mar 05 '17 at 19:10

score 0 · Accepted Answer · answered Mar 05 '17 at 20:19

To get realtime feedback you need to subscribe to changes,and then monitor those changes. Here is an example of watching tasks:

from MeteorClient import MeteorClient

def call_back_added(collection, id, fields):
    print('* ADDED {} {}'.format(collection, id))
    for key, value in fields.items():
        print('  - FIELD {} {}'.format(key, value))

    # query the data each time something has been added to
    # a collection to see the data `grow`
    all_lists = client.find('lists', selector={})
    print('Lists: {}'.format(all_lists))
    print('Num lists: {}'.format(len(all_lists)))

client = MeteorClient('ws://localhost:3000/websocket')
client.on('added', call_back_added)
client.connect()
client.subscribe('tasks')

# (sort of) hacky way to keep the client alive
# ctrl + c to kill the script
while True:
    try:
        time.sleep(1)
    except KeyboardInterrupt:
        break

client.unsubscribe('tasks')

(Reference) (Docs)

See real time changes in data using python meteor

1 Answers1