How to efficiently parse emails without touching attachments using Python

Question

I'm playing with Python imaplib (Python 2.6) to fetch emails from GMail. Everything I fetch an email with method http://docs.python.org/library/imaplib.html#imaplib.IMAP4.fetch I get whole email. I need only text part and also parse names of attachments, without downloading them. How this can be done? I see that emails returned by GMail follow the same format that browsers send to HTTP servers.

Answer 1

Take a look at this recipe: http://code.activestate.com/recipes/498189/

I adapted it slightly to print the From, Subject, Date, name of attachments, and message body (just plaintext for now -- its trivial to add html messages).

I used the Gmail pop3 server in this case, but it should work for IMAP as well.

import poplib, email, string

mailserver = poplib.POP3_SSL('pop.gmail.com')
mailserver.user('recent:YOURUSERNAME') #use 'recent mode'
mailserver.pass_('YOURPASSWORD') #consider not storing in plaintext!

numMessages = len(mailserver.list()[1])
for i in reversed(range(numMessages)):
    message = ""
    msg = mailserver.retr(i+1)
    str = string.join(msg[1], "\n")
    mail = email.message_from_string(str)

    message += "From: " + mail["From"] + "\n"
    message += "Subject: " + mail["Subject"] + "\n"
    message += "Date: " + mail["Date"] + "\n"

    for part in mail.walk():
        if part.is_multipart():
            continue
        if part.get_content_type() == 'text/plain':
            body = "\n" + part.get_payload() + "\n"
        dtypes = part.get_params(None, 'Content-Disposition')
        if not dtypes:
            if part.get_content_type() == 'text/plain':
                continue
            ctypes = part.get_params()
            if not ctypes:
                continue
            for key,val in ctypes:
                if key.lower() == 'name':
                    message += "Attachment:" + val + "\n"
                    break
            else:
                continue
        else:
            attachment,filename = None,None
            for key,val in dtypes:
                key = key.lower()
                if key == 'filename':
                    filename = val
                if key == 'attachment':
                    attachment = 1
            if not attachment:
                continue
            message += "Attachment:" + filename + "\n"
        if body:
            message += body + "\n"
    print message
    print

This should be enough to get you heading in the right direction.

Answer 2

You can get only the plain text of the email by doing something like:

connection.fetch(id, '(BODY[1])')

For the gmail messages I've seen, section 1 has the plaintext, including multipart junk. This may not be so robust.

I don't know how to get the name of the attachment without all of it. I haven't tried using partials.