Python Lambda script for connecting to a RDS MySQL instance

lambda_function.py

import json
import pymysql
import os

def lambda_handler(event, context):
    # Establish a connecto the the MySQL database
    connection = pymysql.connect(host=os.environ['db_host'], user=os.environ['db_username'], password=os.environ['db_password'], database=os.environ['db_name'])
    
    # Add a new user and print the updated user list
    add_new_user(connection, 'JohnDoe', 'johndoe@example.com')
    print_user_list(connection)

    # Close the connection
    connection.close()
        
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }

# Function to add a new user
def add_new_user(connection, username, email):
    try:
        with connection.cursor() as cursor:
            sql = "INSERT INTO users (username, email) VALUES (%s, %s)"
            cursor.execute(sql, (username, email))
        connection.commit()
        print("New user added successfully!")

    except Exception as e:
        connection.rollback()
        print(f"Error adding user: {e}")

# Function to retrieve and print the user list
def print_user_list(connection):
    try:
        with connection.cursor() as cursor:
            cursor = connection.cursor(pymysql.cursors.DictCursor)  # Using DictCursor
            sql = "SELECT * FROM users"
            cursor.execute(sql)
            users = cursor.fetchall()

            print("List of users:")
            for user in users:
                print(f"ID: {user['id']} | Username: {user['username']} | Email: {user['email']} | Created At: {user['created_at']}")

    except Exception as e:
        print(f"Error retrieving user list: {e}")