The nntplib Module

The nntplib module provides a Network News Transfer Protocol (NNTP) client implementation.

7.17.1 Listing messages

Prior to reading messages from a news server, you have to connect to the server and then select a newsgroup. The script in Example 7-32 also downloads a complete list of all messages on the server and extracts some more or less interesting statistics from that list.

Example 7-32. Using the nntplib Module to List Messages

File: nntplib-example-1.py

import nntplib
import string

SERVER = "news.spam.egg"
GROUP = "comp.lang.python" 
AUTHOR = "fredrik@pythonware.com" # eff-bots human alias

# connect to server
server = nntplib.NNTP(SERVER)

# choose a newsgroup
resp, count, first, last, name = server.group(GROUP)
print "count", "=>", count
print "range", "=>", first, last

# list all items on the server
resp, items = server.xover(first, last)

# extract some statistics
authors = {}
subjects = {}
for id, subject, author, date, message_id, references, size, lines in items:
 authors[author] = None
 if subject[:4] == "Re: ":
 subject = subject[4:]
 subjects[subject] = None
 if string.find(author, AUTHOR) >= 0:
 print id, subject
 
print "authors", "=>", len(authors)
print "subjects", "=>", len(subjects)

count => 607
range => 57179 57971
57474 Three decades of Python!
...
57477 More Python books coming...
authors => 257
subjects => 200

7.17.2 Downloading Messages

Downloading a message is easy. Just call the article method, as shown in Example 7-33.

Example 7-33. Using the nntplib Module to Download Messages

File: nntplib-example-2.py

import nntplib
import string

SERVER = "news.spam.egg"
GROUP = "comp.lang.python" 
KEYWORD = "tkinter"

# connect to server
server = nntplib.NNTP(SERVER)

resp, count, first, last, name = server.group(GROUP)
resp, items = server.xover(first, last)
for id, subject, author, date, message_id, references, size, lines in items:
 if string.find(string.lower(subject), KEYWORD) >= 0:
 resp, id, message_id, text = server.article(id)
 print author
 print subject
 print len(text), "lines in article"

"Fredrik Lundh" 
Re: Programming Tkinter (In Python)
110 lines in article
...

Example 7-34 shows how you can further manipulate the messages by wrapping it up in a Message object (using the rfc822 module).

Example 7-34. Using the nntplib and rfc822 Modules to Process Messages

File: nntplib-example-3.py

import nntplib
import string, random
import StringIO, rfc822

SERVER = "news.spam.egg"
GROUP = "comp.lang.python"

# connect to server
server = nntplib.NNTP(SERVER)

resp, count, first, last, name = server.group(GROUP)
for i in range(10):
 try:
 id = random.randint(int(first), int(last))
 resp, id, message_id, text = server.article(str(id))
 except (nntplib.error_temp, nntplib.error_perm):
 pass # no such message (maybe it was deleted?)
 else:
 break # found a message!
else:
 raise SystemExit

text = string.join(text, "
")
file = StringIO.StringIO(text)

message = rfc822.Message(file)

for k, v in message.items():
 print k, "=", v

print message.fp.read()

mime-version = 1.0
content-type = text/plain; charset="iso-8859-1"
message-id = <008501bf1417$1cf90b70$f29b12c2@sausage.spam.egg>
lines = 22
...
from = "Fredrik Lundh" 
nntp-posting-host = parrot.python.org
subject = ANN: (the eff-bot guide to) The Standard Python Library
...

Once you've gotten this far, you can use modules like htmllib, uu, and base64 to further process the messages.

Core Modules

More Standard Modules

Threads and Processes

Data Representation

File Formats

Mail and News Message Processing

Network Protocols

Internationalization

Multimedia Modules

Data Storage

Tools and Utilities

Platform-Specific Modules

Implementation Support Modules

Other Modules



Python Standard Library
Python Standard Library (Nutshell Handbooks) with
ISBN: 0596000960
EAN: 2147483647
Year: 2000
Pages: 252
Authors: Fredrik Lundh

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