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):
        …

13 0 Open

Errors & debugging medium

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)
    …

11 0 Open

Errors & debugging easy

How to Wrap a Low Level Error in a Higher Level Exception in Python

Wrap low-level exceptions in a higher-level exception while preserving the original cause with the `from` keyword.

exception-chaining error-handling wrapping

Python

class LowLevelError(Exception):
    pass

class HighLevelError(Exception):
    pass

def low_level_operation():
    raise LowLevelError("storage drive failed to respond")

def high_level_operation():
    try:
        low_level_operation()
    except LowLevelError as e:
        raise HighLevelError(f"database operation…

13 0 Open

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