#coding: utf-8
'''
春运查询火车票转让信息
Author: piglei2007@gmail.com
Date: 2011.01.25
'''
import re
import os
import time
import urlparse
import datetime
import traceback
import urllib2
import socket
socket.setdefaulttimeout(20)

BLANK_RE = re.compile(r"s+")

opener = urllib2.build_opener(urllib2.HTTPCookieProcessor())
opener.addheaders = [
 ("User-agent", "Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.9.1) Gecko/20090704 Firefox/3.5"),
 ("Accept", "*/*"),
]
urllib2.install_opener(opener)

from BeautifulSoup import BeautifulSoup

SOURCE = {
 "58": "http://bj.58.com/huochepiao/?Num=%(train)s&StartTime=%(date)s00",
 "ganji": "http://bj.ganji.com/piao/cc_%(train)s/%(date)s/",
}
RECORD_FILE = "/tmp/ticket_records.txt"

def parse_record():
 try:
 return set([x.strip() for x in open(RECORD_FILE, "r").readlines()])
 except IOError:
 open(RECORD_FILE, "w")
 return set()

def flush_record(records):
 open(RECORD_FILE, "w").write("
".join(records))

def main(config):
 """
 开始抓取
 """
 existed = parse_record()
 to_email = []

 for train in config["trains"]:
 for date in config["dates"]:
 for type, _url in SOURCE.items():
 url = _url % dict(train=train, date=date)
 content = urllib2.urlopen(url).read()
 soup = BeautifulSoup(content)
 result = parse_content(type, soup, train)
 for url, text in result:
 url = urlparse.urljoin(_url, url)
 # 只要卧铺！
 if url not in existed and u"卧" in text:
 to_email.append([text, url])
 existed.add(url)
 if to_email:
 content = "".join(
 [x for x in [" | ".join(y) for y in to_email]]
 ).encode("utf-8")
 simple_mail(config["people"], content)
 flush_record(existed)

def parse_content(type, soup, train):
 """
 获得车次信息
 """
 result = []
 if type == "58":
 info_table = soup.find("table", id="infolist")
 if info_table:
 for x in info_table.findAll("tr", text=re.compile(ur"%s(?!时刻表)" % train, re.I)):
 a = x.parent
 _text = BLANK_RE.sub("", a.text)
 result.append([a["href"], _text])
 if type == "ganji":
 for x in soup.findAll("dl", {"class": "list_piao"}):
 a = x.dt.a
 result.append([a["href"], a.text])
 return result

EMAIL_HOST = 'smtp.sohu.com'
EMAIL_HOST_USER = 'yourname@sohu.com'
EMAIL_HOST_PASSWORD = 'yourpassword'
EMAIL_PORT = 25

def simple_mail(to, content):
 """
 发送邮件
 """
 import smtplib
 from email.mime.text import MIMEText

 msgRoot = MIMEText(content, 'html', 'UTF-8')
 msgRoot['Subject'] = "[%s]有票来啦！！！！" % datetime.datetime.today().isoformat(" ")
 msgRoot['From'] = EMAIL_HOST_USER
 msgRoot['To'] = ", ".join(to)

 s = smtplib.SMTP(EMAIL_HOST, EMAIL_PORT)
 s.login(EMAIL_HOST_USER, EMAIL_HOST_PASSWORD)
 s.sendmail(EMAIL_HOST_USER, to, msgRoot.as_string())
 s.close()

def switch_time_zone():
 """
 切换时区
 """
 os.environ["TZ"] = "Asia/Shanghai"
 time.tzset()

switch_time_zone()

if __name__ == '__main__':
 config = {
 "trains": ("k471",),
 "dates": ("20110129",),
 "people": (
 "youremail@sohu.com",
 )
 }
 try:
 main(config)
 print "%s: ok" % datetime.datetime.today()
 except Exception, e:
 print traceback.format_exc()

然后放入cron，你懂的。