Error Handling Strategies

Purpose

Implement robust error handling that gracefully manages failures, provides clear feedback, and maintains system stability.

When to Use

• Writing any code that can fail
• Handling external API calls
• Processing user input
• Managing file I/O operations
• Dealing with network requests

Key Capabilities

1. Error Detection - Identify potential failure points
2. Error Recovery - Implement fallback strategies
3. Error Communication - Provide clear, actionable messages

Approach

1. Identify what can go wrong (invalid input, network failure, etc.)
2. Validate inputs before processing
3. Use try-catch or error returns appropriately
4. Provide context in error messages
5. Log errors with sufficient debugging information
6. Implement retry logic for transient failures

Example

Context: File reading operation

def read_config(filepath):
    try:
        with open(filepath, 'r') as f:
            return json.load(f)
    except FileNotFoundError:
        logger.error(f"Config file not found: {filepath}")
        return get_default_config()
    except json.JSONDecodeError as e:
        logger.error(f"Invalid JSON in {filepath}: {e}")
        raise ConfigurationError(f"Config file is malformed at line {e.lineno}")
    except PermissionError:
        logger.error(f"Cannot read {filepath}: Permission denied")
        raise ConfigurationError(f"Insufficient permissions for {filepath}")

Best Practices

• ✅ Fail fast for programming errors
• ✅ Recover gracefully from external failures
• ✅ Include context in error messages
• ❌ Avoid: Silent failures or generic error messages