Reference library

Errors & debugging

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

3 matches

Collect Multiple Validation Errors in Python Before Raising

A chainable Validator class that accumulates all validation errors and raises them together in a single exception.

class ValidationError(Exception):
    pass

class Validator:
    def __init__(self):
        self.errors = []
    
    def validate_required(self, value, field_name):
        if not value:
            self.errors.append(f"{field_name} is required")
        return self
    
    def validate_email(self, email):
        …

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 …

15 0 Open

Errors & debugging medium

How to Print an Exception Chain in Python for Debugging

A helper that walks an exception's __cause__ and __context__ chain, printing each level with indentation to make debugging nested errors clearer.

exception-chain debugging traceback

Python

import sys
import traceback

def pretty_exception_chain(exc):
    """Print the full exception chain with cause/context details."""
    chain = []
    current = exc
    seen = set()
    
    while current is not None and id(current) not in seen:
        seen.add(id(current))
        chain.append(current)
        curren…

12 0 Open

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