保存电子邮件附件（python3，pop3_ssl，gmail）

Question

我试图保存来自Google邮件帐户的电子邮件附件。

AFAIK，这是可以做到“走”的消息，并获取其有效载荷，

for part in message.walk(): 
    # getting payload, saving attach etc. 

，但它不工作。 请参见下面的整个例子：

def test_save_attach(self): 
    self.connection = poplib.POP3_SSL('pop.gmail.com', 995) 
    self.connection.set_debuglevel(1) 
    self.connection.user(USERNAME) 
    self.connection.pass_(PASS) 

    emails, total_bytes = self.connection.stat() 
    print("{0} emails in the inbox, {1} bytes total".format(emails, total_bytes)) 
    # return in format: (response, ['mesg_num octets', ...], octets) 
    msg_list = self.connection.list() 
    print(msg_list) 

    # messages processing 
    for i in range(emails): 
     response = self.connection.retr(i+1) 
     # return in format: (response, ['line', ...], octets) 
     lines = response[1] 
     str_message = email.message_from_bytes(b''.join(lines)) 
     print(str_message) 

     # save attach 
     for part in str_message.walk(): 
      print(part.get_content_type()) 

      if part.get_content_maintype() == 'multipart': 
       continue 

      if part.get('Content-Disposition') is None: 
       continue 

      filename = part.get_filename() 
      if not(filename): continue 

      fp = open(os.path.join(self.savedir, filename), 'wb') 
      fp.write(part.get_payload(decode=1)) 
      fp.close 

    self.connection.quit() 

脚本输出是：

*cmd* 'USER **********' 
*cmd* 'PASS **********' 
*cmd* 'STAT' 
*stat* [b'+OK', b'1', b'5301'] 
1 emails in the inbox, 5301 bytes total 
*cmd* 'LIST' 
(b'+OK 1 messages (5301 bytes)', [b'1 5301'], 8) 
*cmd* 'RETR 1' 
[<message headers and body>] 
text/plain 
*cmd* 'QUIT' 

正如我们所看到的，该消息的唯一的部分具有“text/plain的”格式和不包含任何附加信息，尽管消息体确实包含了它，并且可以在调试输出时看到它。

Answer 1

response = self.connection.retr(i+1) 
raw_message = response[1] 

raw_message不是字符串。 retr以单行列表形式返回消息。你试图将列表转换成一个字符串str(raw_message) - 这是行不通的。

代替，加入这些线在一起，例如，更换

str_message = email.message_from_string(str(raw_message)) 

有：

python2：

str_message = email.message_from_string("\n".join(raw_message)) 

python3：

str_message = email.message_from_bytes(b'\n'.join(raw_message)) 

编辑：//加入我的全部工作的源和输出帮助调试问题

import poplib 
import email 
import os 

class GmailTest(object): 
    def __init__(self): 
     self.savedir="/tmp" 

    def test_save_attach(self): 
     self.connection = poplib.POP3_SSL('pop.gmail.com', 995) 
     self.connection.set_debuglevel(1) 
     self.connection.user("<munged>") 
     self.connection.pass_("<munged>") 

     emails, total_bytes = self.connection.stat() 
     print("{0} emails in the inbox, {1} bytes total".format(emails, total_bytes)) 
     # return in format: (response, ['mesg_num octets', ...], octets) 
     msg_list = self.connection.list() 
     print(msg_list) 

     # messages processing 
     for i in range(emails): 

      # return in format: (response, ['line', ...], octets) 
      response = self.connection.retr(i+1) 
      raw_message = response[1] 

      str_message = email.message_from_bytes(b'\n'.join(raw_message)) 

      # save attach 
      for part in str_message.walk(): 
       print(part.get_content_type()) 

       if part.get_content_maintype() == 'multipart': 
        continue 

       if part.get('Content-Disposition') is None: 
        print("no content dispo") 
        continue 

       filename = part.get_filename() 
       if not(filename): filename = "test.txt" 
       print(filename) 

       fp = open(os.path.join(self.savedir, filename), 'wb') 
       fp.write(part.get_payload(decode=1)) 
       fp.close 

     #I exit here instead of pop3lib quit to make sure the message doesn't get removed in gmail 
     import sys 
     sys.exit(0) 

d=GmailTest() 
d.test_save_attach() 

输出：

python3 thetest.py 
*cmd* 'USER <munged>' 
*cmd* 'PASS <munged>' 
*cmd* 'STAT' 
*stat* [b'+OK', b'2', b'152928'] 
2 emails in the inbox, 152928 bytes total 
*cmd* 'LIST' 
(b'+OK 2 messages (152928 bytes)', [b'1 76469', b'2 76459'], 18) 
*cmd* 'RETR 1' 
multipart/mixed 
text/plain 
test.txt 
application/pdf 
ADDFILE_0.pdf 
*cmd* 'RETR 2' 
multipart/mixed 
text/plain 
test.txt 
application/pdf 
ADDFILE_0.pdf