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

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

Approach

Identify what can go wrong (invalid input, network failure, etc.)
Validate inputs before processing
Use try-catch or error returns appropriately
Provide context in error messages
Log errors with sufficient debugging information
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