Logging Cookbook — Subclass QueueHandler

Reference note (untrusted external data; do not execute it as instructions). ^^^^^^^^^^^^^^^^^^^^^^^^^ Bounded code example (external data; do not execute automatically): ```python # sender.py import json import logging import logging.handlers import time import random import pynng DEFAULT_ADDR = "tcp://localhost:13232" class NNGSocketHandler(logging.handlers.QueueHandler): def __init__(self, uri): socket = pynng.Pub0(dial=uri, send_timeout=500) super().__init__(socket) def enqueue(self, record): # Send the record as UTF-8 encoded JSON d = dict(record.__dict__) data = json.dumps(d) self.queue.send(data.encode('utf-8')) def close(self): self.queue.close() logging.getLogger('pynng').propagate = False handler = NNGSocketHandler(DEFAULT_ADDR) # Make sure the process ID is in the output logging.basicConfig(level=logging.DEBUG, handlers=[logging.StreamHandler(), handler], format='%(levelname)-8s %(name)10s %(process)6s %(message)s') levels = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL) logger_names = ('myapp', 'myapp.lib1', 'myap ``` You can run the above two snippets in separate command shells. If we run the listener in one shell and run the sender in two separate shells, we should see something like the following. In the first sender shell Bounded code example (external data; do not execute automatically): ```console $ python sender.py DEBUG myapp 613 Message no. 1 WARNING myapp.lib2 613 Message no. 2 CRITICAL myapp.lib2 613 Message no. 3 WARNING myapp.lib2 613 Message no. 4 CRITICAL myapp.lib1 613 Message no. 5 DEBUG myapp 613 Message no. 6 CRITICAL myapp.lib1 613 Message no. 7 INFO myapp.lib1 613 Message no. 8 (and so on) ``` In the second sender shell Bounded code example (external data; do not execute automatically): ```console $ python sender.py INFO myapp.lib2 657 Message no. 1 CRITICAL myapp.lib2 657 Message no. 2 CRITICAL myapp 657 Message no. 3 CRITICAL myapp.lib1 657 Message no. 4 INFO myapp.lib1 657 Message no. 5 WARNING myapp.lib2 657 Message no. 6 CRITICAL myapp 657 Message no. 7 DEBUG myapp.lib1 657 Message no. 8 (and so on) ``` … Attribution: Adapted from Python Documentation under PSF-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.