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Errors & debugging

Handle failures gracefully, raise helpful errors, and debug with confidence.

3 matches

How to Configure Python Logging with File Rotation

A complete demo that sets up a logger with a rotating file handler, writes several log entries, and shows the contents of the current log file.

logging file-handler rotating-file-handler

Python

import logging
from logging.handlers import RotatingFileHandler

logger = logging.getLogger("rotating_logger")
logger.setLevel(logging.DEBUG)

file_handler = RotatingFileHandler(
    "app.log",
    maxBytes=100,
    backupCount=3
)
file_handler.setFormatter(
    logging.Formatter("%(asctime)s - %(levelname)s - %(messa…

13 0 Open

Errors & debugging medium

How to Diff Two Dicts in Python for Config Drift

Recursively compare two dictionaries and report added, removed, and changed keys with their old and new values for debugging configuration drift.

dict diff config

Python

def diff_dicts(a, b, path=""):
    differences = []

    for key in a.keys() | b.keys():
        new_path = f"{path}.{key}" if path else key

        if key not in a:
            differences.append((new_path, "<missing>", b[key], "added"))
        elif key not in b:
            differences.append((new_path, a[key], "<…

12 0 Open

Errors & debugging easy

Log to stderr with Python logging basicConfig

Configure Python's logging module to send all log messages to standard error (stderr) instead of the default stderr, with a readable timestamped format.

logging stderr debugging

Python

import logging

def main():
    logging.basicConfig(
        level=logging.DEBUG,
        format="%(asctime)s — %(name)s — %(levelname)s — %(message)s",
        stream=__import__("sys").stderr,
    )
    logger = logging.getLogger("example")
    logger.debug("Debug message")
    logger.info("Info message")
    logger.…

12 0 Open

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