Reference library

Errors & debugging

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

5 matches

How to Build a Simple Debug Timer in Python

Create a context manager class to time the execution of a code block with a one-line printout.

import time


class DebugTimer:
    """Context manager that times the execution of a code block."""

    def __init__(self, label="Operation"):
        self.label = label
        self.start_time = None

    def __enter__(self):
        self.start_time = time.perf_counter()
        return self

    def __exit__(self, e…

16 0 Open

Errors & debugging medium

How to Simulate Timeout with Custom TimeoutError in Python

Run a function in a daemon thread and raise a custom TimeoutError if it exceeds a specified time limit.

timeout threading exceptions

Python

import time
from typing import Callable, TypeVar

T = TypeVar("T")


class TimeoutError(Exception):
    """Raised when an operation exceeds its time limit."""

    def __init__(self, message: str = "Operation timed out"):
        self.message = message
        super().__init__(self.message)


def run_with_timeout(func…

13 0 Open

Errors & debugging medium

Implement circuit breaker open after failures demo in Python

A minimal CircuitBreaker class that calls a function and automatically 'opens' after a set number of consecutive failures, blocking further calls with a RuntimeError.

circuit-breaker resilience error-handling

Python

import time
from datetime import datetime


class CircuitBreaker:
    def __init__(self, threshold=3):
        self.threshold = threshold
        self.failure_count = 0
        self.is_open = False

    def call(self, func, *args, **kwargs):
        if self.is_open:
            raise RuntimeError("Circuit is OPEN")
  …

13 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.…

13 0 Open

Errors & debugging easy

Retry an Operation on ConnectionError in Python

Retries an unreliable operation a fixed number of times when it raises a transient ConnectionError, with a small delay between attempts.

retry connection-error error-handling

Python

import time
import random


def unreliable_operation():
    """Simulates an operation that throws ConnectionError occasionally."""
    if random.random() < 0.6:
        raise ConnectionError("Transient network failure")
    return "Operation succeeded"


def retry_operation(attempts=4, delay=0.2):
    """Retries the o…

15 0 Open

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