Python IMAPClient 库和电子邮件包之间的交互

Question

我有一个 Django 项目，我正在其中开发电子邮件客户端。我决定使用 python 的 IMAPClient instead of standard library's imaplib for getting access to the messages. Currently, I don't make use of python's email package to encode/decode responses received from IMAPClient, and I have a feeling that I manually implement things that should be handled by email.

下载附件的示例代码：

def download_attachment(server, msgid, index, encoding):
    # index and encoding is known from previous analysis of bodystructure
    file_content = f_fetch(server, msgid, index)
    # the below code should be handled by email's message_from_bytes 
    # and subsequent get_payload(decode = True) function
    if encoding == 'base64':
        file_content = base64.b64decode(file_content)
    elif ...
    ...
    endif
    #writing file_content to a folder
    return

def f_fetch(server, msgid, index):
    if not index:
        index = '1'
    response = server.fetch(msgid, 'BODY[' + index + ']')
    key = ('BODY[' + index + ']').encode('utf-8')
    if type(msgid) is str:
        msgid = int(msgid)
    return response[msgid][key]

所以问题是，我应该如何重写这段代码以利用email。具体来说，我应该如何处理 IMAPClient 的响应以将其传递给电子邮件的 message_from_bytes() 函数？

Answer 1

如果您希望使用电子邮件包的 message_from_bytes() 函数解析电子邮件，那么您需要为其提供完整的原始电子邮件正文。要得到这个，使用 RFC822 选择器像这样获取：

fetch_data = server.fetch(msgid, ['RFC822'])
parsed = email.message_from_bytes(fetch_data[msgid][b'RFC822'])

如果您从 IMAP 服务器中提取单个邮件 parts/attachments，则服务器会有效地为您完成解析工作，您不需要使用电子邮件包的解析器。

Python IMAPClient 库和电子邮件包之间的交互

Interaction between Python IMAPClient library and email package

python

email

imap

imapclient