Manipulando registros com Python e PostgreSQL

crud_psycopg2.py

import psycopg2

class ecommerce_database:
     def __init__(self, cod_product, val_product):
        pass

     def connection_database(self):
        connection = psycopg2.connect(host='localhost', 
                         database='DB_ECOMMERCE',
                         user='postgres', 
                         password='postgres')
        return connection

     def create(self, cod_product: int, val_product: float):
        __sql_insert = f"INSERT INTO TBL_PRODUCTS (COD_PRODUCT, VAL_PRODUCT) VALUES ({cod_product}, {val_product})"
        connection = self.connection_database()
        cursor = connection.cursor()         
        try:
            cursor.execute(__sql_insert)        
            connection.commit()    
        except Exception as error:         
            print("Error: ", error)
            connection.rollback()       
        cursor.close()
            
        def read(self) -> list: 
          connection = self.connection_database() 
          cursor = connection.cursor() 
          cursor.execute("SELECT * FROM TBL_PRODUCTS") 
          records = [record for record in cursor.fetchall()] 
          connection.close() 
          return records
 
        def update(self, cod_product: int, val_product: float): 
          __sql_update = f"UPDATE TBL_PRODUCTS SET VAL_PRODUCT = {val_product} WHERE COD_PRODUCT = {cod_product}"
          connection = self.connection_database() 
          cursor = connection.cursor() 
          try: 
             cursor.execute(__sql_update) 
             connection.commit()
          except Exception as error:
             print("Error: ", error)
             connection.rollback() 
          cursor.close()
        
        def delete(self, cod_product):
           if cod_product in self.read(): 
              __sql_delete = f"DELETE FROM TBL_PRODUCTS WHERE COD_PRODUCT = {cod_product}" 
              connection = self.connection_database() 
              cursor = connection.cursor() 
              cursor.execute(__sql_delete) 
              connection.commit() 
              cursor.close() 
           else: 
              print("cod_product not found in TBL_PRODUCTS")