poplib
— POP3 协议客户端
¶
源代码: Lib/poplib.py
This module defines a class,
POP3
, which encapsulates a connection to a POP3 server and implements the protocol as defined in
RFC 1939
。
POP3
class supports both the minimal and optional command sets from
RFC 1939
。
POP3
class also supports the
STLS
command introduced in
RFC 2595
to enable encrypted communication on an already established connection.
Additionally, this module provides a class
POP3_SSL
, which provides support for connecting to POP3 servers that use SSL as an underlying protocol layer.
Note that POP3, though widely supported, is obsolescent. The implementation quality of POP3 servers varies widely, and too many are quite poor. If your mailserver supports IMAP, you would be better off using the
imaplib.IMAP4
class, as IMAP servers tend to be better implemented.
poplib
module provides two classes:
poplib.
POP3
(
host
,
port=POP3_PORT
[
,
timeout
]
)
¶
This class implements the actual POP3 protocol. The connection is created when the instance is initialized. If port is omitted, the standard POP3 port (110) is used. The optional timeout parameter specifies a timeout in seconds for the connection attempt (if not specified, the global default timeout setting will be used).
poplib.
POP3_SSL
(
host
,
port=POP3_SSL_PORT
,
keyfile=None
,
certfile=None
,
timeout=None
,
context=None
)
¶
This is a subclass of
POP3
that connects to the server over an SSL encrypted socket. If
port
is not specified, 995, the standard POP3-over-SSL port is used.
timeout
works as in the
POP3
构造函数。
context
is an optional
ssl.SSLContext
object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read
安全注意事项
for best practices.
keyfile and certfile are a legacy alternative to context - they can point to PEM-formatted private key and certificate chain files, respectively, for the SSL connection.
3.2 版改变: context 参数被添加。
3.4 版改变:
The class now supports hostname check with
ssl.SSLContext.check_hostname
and
Server Name Indication
(见
ssl.HAS_SNI
).
从 3.6 版起弃用:
keyfile
and
certfile
被弃用代之
context
。请使用
ssl.SSLContext.load_cert_chain()
代替,或让
ssl.create_default_context()
为您选择系统的受信任 CA 证书。
One exception is defined as an attribute of the
poplib
模块:
poplib.
error_proto
¶
Exception raised on any errors from this module (errors from
socket
module are not caught). The reason for the exception is passed to the constructor as a string.
另请参阅
imaplib
All POP3 commands are represented by methods of the same name, in lower-case; most return the response text sent by the server.
An
POP3
实例具有下列方法:
POP3.
set_debuglevel
(
level
)
¶
Set the instance’s debugging level. This controls the amount of debugging output printed. The default,
0
, produces no debugging output. A value of
1
produces a moderate amount of debugging output, generally a single line per request. A value of
2
or higher produces the maximum amount of debugging output, logging each line sent and received on the control connection.
POP3.
getwelcome
(
)
¶
Returns the greeting string sent by the POP3 server.
POP3.
capa
(
)
¶
Query the server’s capabilities as specified in
RFC 2449
. Returns a dictionary in the form
{'name':
['param'...]}
.
3.4 版新增。
POP3.
user
(
username
)
¶
Send user command, response should indicate that a password is required.
POP3.
pass_
(
password
)
¶
Send password, response includes message count and mailbox size. Note: the mailbox on the server is locked until
quit()
被调用。
POP3.
apop
(
user
,
secret
)
¶
Use the more secure APOP authentication to log into the POP3 server.
POP3.
rpop
(
user
)
¶
Use RPOP authentication (similar to UNIX r-commands) to log into POP3 server.
POP3.
stat
(
)
¶
Get mailbox status. The result is a tuple of 2 integers:
(message
count,
mailbox
size)
.
POP3.
list
(
[
which
]
)
¶
Request message list, result is in the form
(response,
['mesg_num
octets',
...],
octets)
。若
which
is set, it is the message to list.
POP3.
retr
(
which
)
¶
Retrieve whole message number
which
, and set its seen flag. Result is in form
(response,
['line',
...],
octets)
.
POP3.
dele
(
which
)
¶
Flag message number which for deletion. On most servers deletions are not actually performed until QUIT (the major exception is Eudora QPOP, which deliberately violates the RFCs by doing pending deletes on any disconnect).
POP3.
rset
(
)
¶
Remove any deletion marks for the mailbox.
POP3.
noop
(
)
¶
Do nothing. Might be used as a keep-alive.
POP3.
quit
(
)
¶
Signoff: commit changes, unlock mailbox, drop connection.
POP3.
top
(
which
,
howmuch
)
¶
Retrieves the message header plus
howmuch
lines of the message after the header of message number
which
. Result is in form
(response,
['line',
...],
octets)
.
The POP3 TOP command this method uses, unlike the RETR command, doesn’t set the message’s seen flag; unfortunately, TOP is poorly specified in the RFCs and is frequently broken in off-brand servers. Test this method by hand against the POP3 servers you will use before trusting it.
POP3.
uidl
(
which=None
)
¶
Return message digest (unique id) list. If
which
is specified, result contains the unique id for that message in the form
'response
mesgnum
uid
, otherwise result is list
(response,
['mesgnum
uid',
...],
octets)
.
POP3.
utf8
(
)
¶
Try to switch to UTF-8 mode. Returns the server response if successful, raises
error_proto
if not. Specified in
RFC 6856
.
3.5 版新增。
POP3.
stls
(
context=None
)
¶
Start a TLS session on the active connection as specified in RFC 2595 . This is only allowed before user authentication
context
parameter is a
ssl.SSLContext
object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read
安全注意事项
for best practices.
This method supports hostname checking via
ssl.SSLContext.check_hostname
and
Server Name Indication
(见
ssl.HAS_SNI
).
3.4 版新增。
Instances of
POP3_SSL
have no additional methods. The interface of this subclass is identical to its parent.
Here is a minimal example (without error checking) that opens a mailbox and retrieves and prints all messages:
import getpass, poplib
M = poplib.POP3('localhost')
M.user(getpass.getuser())
M.pass_(getpass.getpass())
numMessages = len(M.list()[1])
for i in range(numMessages):
for j in M.retr(i+1)[1]:
print(j)
At the end of the module, there is a test section that contains a more extensive example of usage.