Database factory for DBAPI 2.0

database_factory.py

import configparser

class DatabaseFactory(object):

    def __init__(self, filename, encoding=None):
        """instantiate with configuration filename"""
        self._cache = dict()
        self._servers = configparser.ConfigParser()
        self._servers.read(filename, encoding)

    def __del__(self):
        """close all cached connection when deleting"""
        cache = self._cache
        for connection in cache.values():
            connection.close()

    def new(self, name):
        """always create new connection"""
        if name not in self._servers:
            raise KeyError("Server %s not in configuration" % name)

        server = self._servers[name]
        driver = __import__(server.get("$"), globals(), locals())

        return  driver.connect(
            host= server.get("host"),
            port= server.getint("port", fallback=3306),
            database= server.get("database", fallback=None),
            user= server.get("user", fallback=None),
            password= server.get("password", fallback=None)
        )

    def shared(self, name):
        """get connection from cache, create new connection if not exists"""
        if name not in self._cache:
            self._cache[name] = self.new(name)
        return self._cache[name]