Handling exceptions with ThreadedWebsocketManager in Python-Binance

When using ThreadedWebsocketManager with python-binance, handling exceptions can be difficult due to its asynchronous nature and lack of direct access to error messages. However, there are a few ways to handle exceptions effectively.

Why is it hard to catch exceptions?

ThreadedWebsocketManager is designed to handle errors internally, meaning you don’t have direct access to the error message. When an exception occurs, Binance propagates it up the call stack and you don’t get any information about what went wrong.

Solution 1: Wrap in a try-except block

One simple approach is to wrap the code in a try–except block, like this:

import threading
from binance import ThreadedWebsocketManager









Create an instance of ThreadedWebsocketManager
manager = ThreadedWebsocketManager()
def handle_exceptions():
try:

Code that can throw an exception is here
pass
except Exception as e:
print(f"Error: {e}")

Start the manager in a separate thread
thread = threading.Thread(target=handle_exceptions)
thread.start()

This will catch any exceptions thrown by ThreadedWebsocketManager and print the error message. However, it is important to note that this approach may not provide much information about what went wrong.

Solution 2: Use a custom exception handler

Another approach is to create a custom exception handler function that catches specific exceptions and prints the appropriate information:

import logging

Create a logger
logger = logging.getLogger(__name__)
def handle_exceptions():
try:

Here, put code that can throw an exception
pass
except ThreadedWebsocketManager.ConnectionException as e:
logger.error(f"Connection exception: {e}")
except Exception as e:
logger.error(f"Other exception: {e}")

Start the manager in a separate thread
thread = threading.Thread(target=handle_exceptions)
thread.start()

This will catch both ThreadedWebsocketManager.ConnectionException, as well as any other exceptions raised by ThreadedWebsocketManager and print out relevant information about what went wrong.

Solution 3: Use a logging handler

You can also use a custom logging handler to collect error messages from ThreadedWebsocketManager. Here is an example:

import threading
import logging

Create a logger
logger = logging.getLogger(__name__)
class ThreadedWebsocketManagerLogger(logging.Handler):
def emit(self, record):
try:

Code that can cause an exception is here
pass
except Exception as e:
super().emit(record)

Create and start a logger
logger = ThreadedWebsocketManagerLogger()
thread = threading.Thread(target=lambda: logger.handle())
thread.start()

The rest of the code...

This will collect error messages from ThreadedWebsocketManager into a log file.

Conclusion

While there is no direct way to access exception information using ThreadedWebsocketManager, you can use different approaches to handle exceptions efficiently. Wrapping your code in try-except blocks or creating custom exception handlers are simple solutions, while using logging provides more flexibility and control. Choose the approach that best suits your needs.