Python 重新连接到 MySQLdb

Question

我有以下内容:

class DBConnection:
    def __init__(self, DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_NAME):
        self.host = DB_HOST
        self.port = DB_PORT
        self.name = DB_NAME
        self.user = DB_USER
        self.password = DB_PASSWORD
        self.conn = None
        self.cursor = None

    def get_conn(self):
        if self.conn is None:
            self.conn = MySQLdb.connect (host = self.host, port = self.port, db = self.name, user = self.user, passwd = self.password)
        return self.conn

    def close_conn(self):
        if self.conn:
            self.conn.close()
        return self.conn

这就是我尝试重新连接时的样子:

>>> from db_conn import DBConnection
>>> db = DBConnection(DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_NAME)
>>> db.get_conn()
<_mysql.connection open to '127.0.0.1' at 7fbb1b8a2420>
>>> db.close_conn()
>>> db.conn
<_mysql.connection closed at 7fbb1b8a2420>
>>> db.get_conn()
<_mysql.connection closed at 7fbb1b8a2420>

为什么不允许我重新打开连接？我如何重新打开它，或者我是否需要创建一个新实例？

Answer 1

您正在测试 self.conn 是否为“无”，但事实并非如此 - 它仍然是一个 mysql 连接对象。它的一个属性或方法会告诉你它是否打开，所以你可以测试它，或者在 close_conn 中将 self.conn 设置为 None (如果这样更容易的话)。