我正在尝试使用twisted来获取gmail帐户上的电子邮件，并且至少说它一直是一种痛苦，看电子邮件是他们一个明确的解释和结构（它似乎最好被黑客攻击）。我试图抓住附件，但附件不在任何可见的地方。
我正在使用示例IMAP客户端来扭曲和修改它，我使用fetchAll（'1：'）来获取电子邮件然后获取第一封电子邮件但我找不到电子邮件附件在那封电子邮件（我检查它在谷歌）。还有什么是1：，我似乎无法找到任何实际解释电子邮件的东西（好像没有人理解它）
所以Stackoverflow，我错过了什么？
代码
#!/usr/bin/env python
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Simple IMAP4 client which displays the subjects of all messages in a
particular mailbox.
"""
import sys
from twisted.internet import protocol
from twisted.internet import ssl
from twisted.internet import defer
from twisted.internet import stdio
from twisted.mail import imap4
from twisted.protocols import basic
from twisted.python import util
from twisted.python import log
class TrivialPrompter(basic.LineReceiver):
from os import linesep as delimiter
promptDeferred = None
def prompt(self, msg):
assert self.promptDeferred is None
self.display(msg)
self.promptDeferred = defer.Deferred()
return self.promptDeferred
def display(self, msg):
self.transport.write(msg)
def lineReceived(self, line):
if self.promptDeferred is None:
return
d, self.promptDeferred = self.promptDeferred, None
d.callback(line)
class SimpleIMAP4Client(imap4.IMAP4Client):
"""
A client with callbacks for greeting messages from an IMAP server.
"""
greetDeferred = None
def serverGreeting(self, caps):
self.serverCapabilities = caps
if self.greetDeferred is not None:
d, self.greetDeferred = self.greetDeferred, None
d.callback(self)
class SimpleIMAP4ClientFactory(protocol.ClientFactory):
usedUp = False
protocol = SimpleIMAP4Client
def __init__(self, username, onConn):
self.ctx = ssl.ClientContextFactory()
self.username = username
self.onConn = onConn
def buildProtocol(self, addr):
"""
Initiate the protocol instance. Since we are building a simple IMAP
client, we don't bother checking what capabilities the server has. We
just add all the authenticators twisted.mail has. Note: Gmail no
longer uses any of the methods below, it's been using XOAUTH since
2010.
"""
assert not self.usedUp
self.usedUp = True
p = self.protocol(self.ctx)
p.factory = self
p.greetDeferred = self.onConn
p.registerAuthenticator(imap4.PLAINAuthenticator(self.username))
p.registerAuthenticator(imap4.LOGINAuthenticator(self.username))
p.registerAuthenticator(
imap4.CramMD5ClientAuthenticator(self.username))
return p
def clientConnectionFailed(self, connector, reason):
d, self.onConn = self.onConn, None
d.errback(reason)
def cbServerGreeting(proto, username, password):
"""
Initial callback - invoked after the server sends us its greet message.
"""
# Hook up stdio
tp = TrivialPrompter()
stdio.StandardIO(tp)
# And make it easily accessible
proto.prompt = tp.prompt
proto.display = tp.display
# Try to authenticate securely
return proto.authenticate(password
).addCallback(cbAuthentication, proto
).addErrback(ebAuthentication, proto, username, password
)
def ebConnection(reason):
"""
Fallback error-handler. If anything goes wrong, log it and quit.
"""
log.startLogging(sys.stdout)
log.err(reason)
return reason
def cbAuthentication(result, proto):
"""
Callback after authentication has succeeded.
Lists a bunch of mailboxes.
"""
return proto.list("", "*"
).addCallback(cbMailboxList, proto
)
def ebAuthentication(failure, proto, username, password):
"""
Errback invoked when authentication fails.
If it failed because no SASL mechanisms match, offer the user the choice
of logging in insecurely.
If you are trying to connect to your Gmail account, you will be here!
"""
failure.trap(imap4.NoSupportedAuthentication)
return proto.prompt(
"No secure authentication available. Login insecurely? (y/N) "
).addCallback(cbInsecureLogin, proto, username, password
)
def cbInsecureLogin(result, proto, username, password):
"""
Callback for "insecure-login" prompt.
"""
if result.lower() == "y":
# If they said yes, do it.
return proto.login(username, password
).addCallback(cbAuthentication, proto
)
return defer.fail(Exception("Login failed for security reasons."))
def cbMailboxList(result, proto):
"""
Callback invoked when a list of mailboxes has been retrieved.
"""
result = [e[2] for e in result]
s = '\n'.join(['%d. %s' % (n + 1, m) for (n, m) in zip(range(len(result)), result)])
if not s:
return defer.fail(Exception("No mailboxes exist on server!"))
return proto.prompt(s + "\nWhich mailbox? [1] "
).addCallback(cbPickMailbox, proto, result
)
def cbPickMailbox(result, proto, mboxes):
"""
When the user selects a mailbox, "examine" it.
"""
mbox = mboxes[int(result or '1') - 1]
return proto.examine(mbox
).addCallback(cbExamineMbox, proto
)
def cbExamineMbox(result, proto):
"""
Callback invoked when examine command completes.
Retrieve the subject header of every message in the mailbox.
"""
# FETCH ALL HEADERS? WHERE IS A ONE FOR AN ATTACHMENT
return proto.fetchAll('1:*').addCallback(cbFetch, proto)
def cbFetch(result, proto):
"""
Finally, display headers.
"""
if result:
keys = result.keys()
keys.sort()
k = keys[-1]
proto.display('%s %s' % (k, result[k]))
else:
print "Hey, an empty mailbox!"
return proto.logout()
def cbClose(result):
"""
Close the connection when we finish everything.
"""
from twisted.internet import reactor
reactor.stop()
def main():
hostname = raw_input('IMAP4 Server Hostname: ')
port = raw_input('IMAP4 Server Port (the default is 143, 993 uses SSL): ')
username = raw_input('IMAP4 Username: ')
password = util.getPassword('IMAP4 Password: ')
onConn = defer.Deferred(
).addCallback(cbServerGreeting, username, password
).addErrback(ebConnection
).addBoth(cbClose)
factory = SimpleIMAP4ClientFactory(username, onConn)
from twisted.internet import reactor
if port == '993':
reactor.connectSSL(hostname, int(port), factory, ssl.ClientContextFactory())
else:
if not port:
port = 143
reactor.connectTCP(hostname, int(port), factory)
reactor.run()
if __name__ == '__main__':
main()
答案 0 :(得分：4)
首先，imap4是一个（可能是不必要的）复杂的邮件处理协议，而twisted的客户端实现（必然）很复杂，完全支持该协议。为了获得更多的地方，你应该考虑花一些时间阅读解释协议的标准：rfc3501和twisted's api的相关部分。
也就是说，看起来你正在使用IMAP4Client.fetchAll()，这自相矛盾地提取了“信封”数据，信息的标题和元数据。返回电子邮件正文的可比调用实际上也是fetchFull()。
答案 1 :(得分：0)
感谢SingleNegationElimination和Jean-Paul指向RFC3501和RFC822的指针，我认为我对如何实现这一目标有了更好的理解。
我找到的解决方案是针对fetchSpecific的API imap4 source code。您可以指定要检索的消息的“部分”（即收件箱中的邮件）。对于附件，附件文件的内容嵌入在TEXT部分中，并使用base64进行编码。在我的特定示例中，邮件中包含pdf附件，并且
proto.fetchSpecific(imap4.MessageSet(247), uid=True, headerType='TEXT').addCallback(cbViewAttachment, proto)
def cbViewAttachment(result, proto):
for k, value in result.items():
print(value[0][4][:400])
...
给出类似的东西
------_CANON_2007111239350128_
Content-Type: Application/pdf;
name="0128_20200711123935_001.pdf"
Content-Disposition: attachment;
filename="0128_20200711123935_001.pdf"
Content-Transfer-Encoding: base64
JVBERi0xLjYKJeLjz9MNCjEgMCBvYmoKPDwgCi9DcmVhdGlvbkRhdGUgKEQ6MjAyMDA3MTEyMDM5
MThaMDAnMDAnKQovQ3JlYXRvciAoXDM3NlwzNzdcMDAwQ1wwMDBhXDAwMG5cMDAwb1wwMDBuXDAw
MCBcMDAwTVwwMDBGXDAwMDJcMDAwNFw
一些简短的解释。上面的代码确实以UID = 247提取了消息的TEXT部分。对fetchSpecific的调用成功后，将调用cbDownloadAttachment，其中第一个参数是{{ 1}}部分-每个指定的消息都有一个条目。在这种情况下，仅指定了一条消息，因此TEXT只是一本字典，只有一个条目对应于UID = 247消息。
实际附件内容嵌入在条目值的result中。看起来像上面。几乎显而易见，[0][4]部分是base64编码的内容。我尝试用JVB...解码它的前一小部分，看起来像
base64这意味着这实际上是PDF文件的开头。
然后，您可以将内容写入本地文件，以便“下载”附件。在上面的示例中，基本上是
%PDF-1.6\n%\xe2\xe3
请注意，213被硬编码为内容的开头。在实际情况下，您绝对应该对with open('your/file/name', 'wb') as f:
f.write(base64.urlsafe_b64decode(value[0][4][213:]))
进行一些解析才能找到答案。
希望这可以帮助处于与我类似状况的人。