Python threaded queue getting empty after putting value init

Question

I am trying to receive live ticks from binance through websocket module and using event (queue) to share the tick data with other libraries. My main file look like this:

<main.py>
from stream import StreamingForexPrices as SF
import threading
import time
import queue

events = queue.Queue()
prices = SF(events)
wst = threading.Thread(target=prices.ws.run_forever, args=[])
wst.daemon = True
wst.start()

while not prices.ws.sock.connected:
    time.sleep(1)
    print("checking1111111")
    print("this", prices.events_queue.get())   ###<<< My code Stuck Here
    # conn_timeout -= 1
while prices.ws.sock is not None:
    # print(prices.ws.sock)
    print("this", prices.events_queue.get())
    print("checking2222222")
    time.sleep(10)

My code just run an infinite loop while not printing any values inside the queue and not showing any error messages in the kernal. I just want to confirm that my program receive the ticks and puts it to the inside the queue for further processing. To reproduce my issue this is the stream module:

from __future__ import print_function

from datetime import datetime
import json, websocket, time
from event import TickEvent

class StreamingForexPrices:
    def __init__(
        self, events_queue
    ):
    self.events_queue = events_queue
    self.prices = dict()
    self.websocket = websocket
    self.socket = f'wss://stream.binance.com:9443/ws/btcusdt@ticker/ethbtc@ticker/bnbbtc@ticker/wavesbtc@ticker/stratbtc@ticker/ethup@ticker/yfiup@ticker/xrpup@ticker'
    self.websocket.enableTrace(False)
    self.ws = self.websocket.WebSocketApp(
        self.socket, on_message=self.on_message, on_close=self.on_close)


def on_close(self, ws, message):
    print("bang")

def on_message(self, ws, message):
    data = json.loads(message)
    self.timestamp = datetime.utcfromtimestamp(data['E']/1000).strftime('%Y-%m-%d %H:%M:%S')
    self.instrument = data['s']
    open = data['o']
    high = data['h']
    low = data['l']
    close = data['c']
    volume = data['v']
    trade = data['n'] #No. of Trades
    # print("testing")
    self.prices[self.instrument]["open"] = open
    self.prices[self.instrument]["high"] = high
    self.prices[self.instrument]["low"] = low
    self.prices[self.instrument]["close"] = close
    self.prices[self.instrument]["volume"] = volume
    self.prices[self.instrument]["trade"] = trade
    tev = TickEvent(self.instrument, self.timestamp, open, high, low, close, volume, trade)
    self.events_queue.put(tev)

Answer 1

You're going to hate this answer.

The PROBLEM here is this statement:

    self.prices[self.instrument]["open"] = open

Why is this a problem? Because self.instrument does not exist as a key in the self.prices dictionary. That causes a KeyError, so nothing ever gets stored in your queue. Normally, you would have received a KeyError that would have told you where the problem was immediately, but the websocket module calls your code in a try/except block that suppresses the errors. You MIGHT consider using your own try/except block and doing your own traceback.

If you add this just before that line:

    if self.instrument not in self.prices:
        self.prices[self.instrument] = {}

then your code all works as you expect.