[Tutor] Logfile Manipulation

[Stephen Nelson-Smith]

Hi,

> If you create iterators from the files that yield (timestamp, entry)
> pairs, you can merge the iterators using one of these recipes:
> http://code.activestate.com/recipes/491285/
> http://code.activestate.com/recipes/535160/

Could you show me how I might do that?

So far I'm at the stage of being able to produce loglines:

#! /usr/bin/env python
import gzip
class LogFile:
  def __init__(self, filename, date):
   self.f=gzip.open(filename,"r")
   for logline in self.f:
     self.line=logline
     self.stamp=" ".join(self.line.split()[3:5])
     if self.stamp.startswith(date):
       break

  def getline(self):
    ret=self.line
    self.line=self.f.readline()
    self.stamp=" ".join(self.line.split()[3:5])
    return ret

logs=[LogFile("a/access_log-20091105.gz","[05/Nov/2009"),LogFile("b/access_log-20091105.gz","[05/Nov/2009"),LogFile("c/access_log-20091105.gz","[05/Nov/2009")]
while True:
  print [x.stamp for x in logs]
  nextline=min((x.stamp,x) for x in logs)
  print nextline[1].getline()


-- 
Stephen Nelson-Smith
Technical Director
Atalanta Systems Ltd
www.atalanta-systems.com