How to write a file generator

From	Billy Mays <noway@nohow.com>
Newsgroups	comp.lang.python
Subject	How to write a file generator
Date	2011-07-12 10:46 -0400
Organization	Aioe.org NNTP Server
Message-ID	<ivhmoc$6t3$1@speranza.aioe.org> (permalink)

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I want to make a generator that will return lines from the tail of 
/var/log/syslog if there are any, but my function is reopening the file 
each call:

def getLines():
     with open('/var/log/syslog', 'rb') as f:
         while True:
             line = f.readline()
             if line:
                 yield line
             else:
                 raise StopIteration


I know the problem lies with the StopIteration, but I'm not sure how to 
tell the caller that there are no more lines for now.

--
Bill

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How to write a file generator Billy Mays <noway@nohow.com> - 2011-07-12 10:46 -0400
  Re: How to write a file generator "bruno.desthuilliers@gmail.com" <bruno.desthuilliers@gmail.com> - 2011-07-12 08:34 -0700
  Re: How to write a file generator Thomas Jollans <t@jollybox.de> - 2011-07-12 17:52 +0200
    Re: How to write a file generator Billy Mays <noway@nohow.com> - 2011-07-12 12:42 -0400
      Re: How to write a file generator Thomas Jollans <t@jollybox.de> - 2011-07-12 21:04 +0200
      Re: How to write a file generator Thomas Jollans <t@jollybox.de> - 2011-07-12 21:05 +0200
  Re: How to write a file generator sturlamolden <sturlamolden@yahoo.no> - 2011-07-12 09:53 -0700
  Re: How to write a file generator Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2011-07-13 01:26 +0200

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