#!/bin/env python
import re, sys
# Define parser first.
def baidu(username):
 # Business logic
 return "Using parser Baidu. and the user's name is: %s." % username
def qzone(uin):
 # Business logic
 return "Using parser Qzone, and the user's QQ is: %s." % uin
# From web.py
def group(seq, size):#{{{
 """
 Returns an iterator over a series of lists of length size from iterable.
  >>> list(group([1,2,3,4], 2))
  [[1, 2], [3, 4]]
  >>> list(group([1,2,3,4,5], 2))
  [[1, 2], [3, 4], [5]]
 """
 def take(seq, n):
  for i in xrange(n):
   yield seq.next()
 if not hasattr(seq, 'next'):
  seq = iter(seq)
 while True:
  x = list(take(seq, size))
  if x:
   yield x
  else:
   break
#}}}
def parser_init(url,mapping):
 for pat, what in group(mapping,2):
  result = re.compile('^' + pat + '$').match(url)
  if result:
   return what, [x for x in result.groups()]
 return None, None
if __name__ == '__main__':
 mapping = (
   'http://(?:hi|space).baidu.com/([^/]+)(?:/.*)?','baidu',
   'http://(\d+).qzone.qq.com(?:/.*)?','qzone',
   )
 (func, args) = parser_init(sys.argv[1],mapping)
 if func:
  callback = func
  if func in globals():
   callback = globals()[func]
  if callable(callback):
   print callback(*args)
 else:
  print 'No parser found.';