ALX Backend Python

This repository contains Python backend development projects focusing on advanced Python concepts, particularly decorators for database operations.

Python Decorators Project (python-decorators-0x01)

This project implements various database operation decorators that showcase different aspects of database management and optimization using Python decorators.

Features

1. SQL Query Logging (0-log_queries.py)

   • Decorator: @log_queries()
   • Logs SQL queries with timestamps before execution
   • Useful for debugging and monitoring database operations

2. Database Connection Management (1-with_db_connection.py)

   • Decorator: @with_db_connection
   • Automatically handles database connection lifecycle
   • Ensures proper connection closure even in case of errors

3. Transaction Management (2-transactional.py)

   • Decorator: @transactional
   • Manages database transactions with automatic commit/rollback
   • Ensures data consistency in database operations

4. Operation Retry Mechanism (3-retry_on_failure.py)

   • Decorator: @retry_on_failure(retries=3, delay=2)
   • Implements retry logic for failed database operations
   • Configurable retry count and delay between attempts

5. Query Result Caching (4-cache_query.py)

   • Decorator: @cache_query
   • Caches query results to improve performance
   • Avoids redundant database calls for identical queries

Usage Examples

1. SQL Query Logging

@log_queries()
def fetch_all_users(query):
    # Function implementation
    pass

users = fetch_all_users(query="SELECT * FROM users")
# Output: [2025-07-18 10:30:15] Query: SELECT * FROM users

2. Database Connection Management

@with_db_connection
def get_user_by_id(conn, user_id):
    # Function implementation using provided connection
    pass

user = get_user_by_id(user_id=1)

3. Transaction Management

@with_db_connection
@transactional
def update_user_email(conn, user_id, new_email):
    # Function implementation with automatic transaction handling
    pass

update_user_email(user_id=1, new_email='new@example.com')

4. Retry Mechanism

@with_db_connection
@retry_on_failure(retries=3, delay=1)
def fetch_users_with_retry(conn):
    # Function implementation with retry capability
    pass

users = fetch_users_with_retry()

5. Query Caching

@with_db_connection
@cache_query
def fetch_users_with_cache(conn, query):
    # Function implementation with result caching
    pass

users = fetch_users_with_cache(query="SELECT * FROM users")

Requirements

• Python 3.x
• SQLite3 (included in Python standard library)

Installation

No additional installation required. The project uses Python's standard library modules:

• sqlite3 for database operations
• functools for decorator utilities
• datetime for timestamp logging
• time for retry delays

Project Structure

python-decorators-0x01/
├── 0-log_queries.py
├── 1-with_db_connection.py
├── 2-transactional.py
├── 3-retry_on_failure.py
└── 4-cache_query.py

Author

• ZEZE1020

License

This project is part of the ALX Backend Python curriculum.