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Errors & debugging

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

3 matches

How to Re-raise Exceptions with 'raise from' in Python

Shows how to re-raise an exception with explicit context chaining using the 'raise ... from ...' syntax, so the original cause is preserved for debugging.

exceptions raise-from error-handling

Python

def divide_with_chain(a, b):
    try:
        result = a / b
        return result
    except ZeroDivisionError as original_error:
        # Re-raise with explicit chaining context
        raise ValueError("Cannot divide by zero") from original_error

def explain_chain():
    try:
        divide_with_chain(10, 0)
    …

12 0 Open

Errors & debugging medium

How to parse a traceback to get the last frame in Python

Extracts the innermost frame's file, line, and function name from a Python traceback object.

traceback exceptions debugging

Python

import sys
import traceback


def parse_traceback_last_frame(exc_info):
    """Return the file, line, and function of the last (innermost) frame."""
    _, _, tb = exc_info
    last_tb = tb
    while last_tb.tb_next is not None:
        last_tb = last_tb.tb_next
    filename = last_tb.tb_frame.f_code.co_filename
    l…

14 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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