types-pymysql

import pymysql from pymysql.cursors import DictCursor import os # These environment variables simulate configuration for a MySQL database. # Replace with your actual database details or set environment variables. DB_HOST = os.environ.get('MYSQL_HOST', 'localhost') DB_USER = os.environ.get('MYSQL_USER', 'root') DB_PASSWORD = os.environ.get('MYSQL_PASSWORD', 'password') DB_NAME = os.environ.get('MYSQL_DB', 'test_db') def get_example_data() -> list[dict]: """Connects to a MySQL database and fetches some example data.""" try: # types-pymysql provides type hints for pymysql.connect's return (Connection) with pymysql.connect( host=DB_HOST, user=DB_USER, password=DB_PASSWORD, database=DB_NAME, cursorclass=DictCursor # Type stubs help with DictCursor return types ) as conn: # 'conn' is typed as 'pymysql.connections.Connection' with conn.cursor() as cursor: # 'cursor' is typed as 'pymysql.cursors.DictCursor' # Type stubs ensure 'execute' and 'fetchall' method signatures are known cursor.execute("SELECT 1 as id, 'hello' as message") result: list[dict] = cursor.fetchall() return result except pymysql.Error as e: print(f"Database connection or query error: {e}") return [] if __name__ == "__main__": # This code requires 'pymysql' to be installed and a running MySQL server. # 'types-pymysql' enhances static analysis of this code. data = get_example_data() if data: print("Fetched data:", data) else: print("Failed to fetch data. Check database connection and `pymysql` installation.")