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Errors & debugging

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

4 matches

How to Add a Correlation ID to Logging Records in Python

Attach a unique correlation ID to every log record using a custom logging.Filter, making distributed request tracking traceable.

logging correlation-id filter

Python

import logging
import uuid
from dataclasses import dataclass, field


@dataclass
class CorrelationIdFilter(logging.Filter):
    correlation_id: str = field(default_factory=lambda: str(uuid.uuid4()))

    def filter(self, record: logging.LogRecord) -> bool:
        record.correlation_id = self.correlation_id
        re…

14 0 Open

Errors & debugging medium

How to Log Errors with Structured Fields in Python

Logs error details as structured dictionary fields using Python's logging module with extra parameters.

logging errors structured

Python

import logging
import sys

def log_structured_error(operation: str, user_id: int, status_code: int, error_msg: str):
    """Log an error with structured fields using a dictionary."""
    logger = logging.getLogger("structured_logger")
    logger.setLevel(logging.ERROR)
    
    # Create console handler if not already …

14 0 Open

Errors & debugging medium

How to attach a request ID to exception messages in Python

This code shows how to enrich exception messages with contextual request IDs using context variables, making error logs more traceable across concurrent requests.

contextvars exception-handling logging

Python

import logging
from contextvars import ContextVar

request_id_var = ContextVar("request_id", default="unknown")

def add_request_id(exc: Exception) -> Exception:
    exc.args = (f"request_id={request_id_var.get()} | {exc.args[0]}" if exc.args else f"request_id={request_id_var.get()}",) + exc.args[1:]
    return exc

d…

12 0 Open

Errors & debugging medium

Redact secrets from log message formatter in Python

Build a custom logging.Formatter that masks passwords, API keys, and credit card numbers in log output.

logging redaction security

Python

import re
import logging

class RedactingFormatter(logging.Formatter):
    """Formatter that masks sensitive data in log messages."""
    
    SENSITIVE_PATTERNS = [
        (re.compile(r'password[=:]\s*\S+', re.IGNORECASE), 'password=[REDACTED]'),
        (re.compile(r'api[_-]?key[=:]\s*\S+', re.IGNORECASE), 'api_key…

14 0 Open

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