connection.py

import psycopg2
import psycopg2.extras

DATABASE_URL = "postgres://cvajuhmapdhtor:fa5a82f16290a2782e4bc6e515812f116dc0733bde5f2f7ff7af92f76a10266b@ec2-54-228-95-1.eu-west-1.compute.amazonaws.com:5432/d75tg1j7gq6pqe"


# def get_connection_string():
#     # setup connection string
#     # to do this, please define these environment variables first
#     user_name = os.environ['PSQL_USER_NAME']
#     password = os.environ['PSQL_PASSWORD']
#     host = os.environ['PSQL_HOST']
#     database_name = os.environ['PSQL_DB_NAME']
#
#     env_variables_defined = user_name and password and host and database_name
#
#     if env_variables_defined:
#         # this string describes all info for psycopg2 to connect to the database
#         return 'postgresql://{user_name}:{password}@{host}/{database_name}'.format(
#             user_name=user_name,
#             password=password,
#             host=host,
#             database_name=database_name
#         )
#     else:
#         raise KeyError('Some necessary environment variable(s) are not defined')


def open_database():
    try:
        connection_string = DATABASE_URL
        connection = psycopg2.connect(connection_string)
        connection.autocommit = True
    except psycopg2.DatabaseError as exception:
        print('Database connection problem')
        raise exception
    return connection


def connection_handler(function):
    def wrapper(*args, **kwargs):
        connection = open_database()
        # we set the cursor_factory parameter to return with a RealDictCursor cursor (cursor which provide dictionaries)
        dict_cur = connection.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
        ret_value = function(dict_cur, *args, **kwargs)
        dict_cur.close()
        connection.close()
        return ret_value

    return wrapper