上下文经理与psycopg2连接到邮政

Question

使用这样的上下文管理器语句进行连接很有用：

with psycopg2.connect(**dns) as conn:
    with conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor) as curs:
...

我应该如何定义一个类别使用上下文管理器与数据库合作的类？

class DBConn:
    def __init__(self, dns):
        self.conn = psycopg2.connect(**dns)
        self.curs = self.conn.cursor()

    def __enter__(self):
        pass

    def __exit__(self):
        pass

Answer 1

知道了...

class DBConn:
    def __init__(self, dns):
        self.connection = psycopg2.connect(**dns)

    def __enter__(self):
        return self.connection.cursor()

    def __exit__(self, exc_type, exc_value, traceback):
        self.connection.commit()
        self.connection.close()