重写imaplib中的open()

Question

因为我发现imaplib不支持超时，所以我尝试覆盖open()函数。但没有成功。我真的不知道我应该继承什么(imaplib或imaplib.IMAP4)，因为模块也有类中没有包含的代码。这是我想要的：

    # Old
    def open(self, host = '', port = IMAP4_PORT):
            self.sock = socket.create_connection((host, port))
            [...]

    # New, what I want to have
    def open(self, host = '', port = IMAP4_port, timeout = 5):
            self.sock = socket.create_connection((host, port), timeout)
            [...]

我只是复制了原始库并对其进行了修改，这很有效，但我不认为这是应该这样做的方式。

有没有人能告诉我一个优雅的方法来解决这个问题？

提前感谢！

Answer 1

好吧，我想我成功了。与其说是纯粹的知识，不如说是一次尝试和错误，但它是有效的。

下面是我所做的：

import imaplib
import socket

class IMAP4(imaplib.IMAP4):
""" Change imaplib to get a timeout """

    def __init__(self, host, port, timeout):
        # Override first. Open() gets called in Constructor
        self.timeout = timeout
        imaplib.IMAP4.__init__(self, host, port)


    def open(self, host = '', port = imaplib.IMAP4_PORT):
        """Setup connection to remote server on "host:port"
            (default: localhost:standard IMAP4 port).
        This connection will be used by the routines:
            read, readline, send, shutdown.
        """
        self.host = host
        self.port = port
        # New Socket with timeout. 
        self.sock = socket.create_connection((host, port), self.timeout)
        self.file = self.sock.makefile('rb')


def new_stuff():
    host = "some-page.com"
    port = 143
    timeout = 10
    try:
        imapcon = IMAP4(host, port, timeout)
        header = imapcon.welcome
    except Exception as e:  # Timeout or something else
        header = "Something went wrong here: " + str(e)
    return header


print new_stuff()

也许这对其他人有帮助。

Answer 2

虽然imaplib不支持超时，但您可以在套接字上设置默认超时，当建立任何套接字连接时都会使用该超时。

socket.setdefaulttimeout(15)

例如：

import socket
def new_stuff():
    host = "some-page.com"
    port = 143
    timeout = 10
    socket.setdefaulttimeout(timeout)
    try:
        imapcon = imaplib.IMAP4(host, port)
        header = imapcon.welcome
    except Exception as e:  # Timeout or something else
        header = "Something went wrong here: " + str(e)
    return header