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Re: Let exception fire or return None

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From Cecil Westerhof <Cecil@decebal.nl>
Newsgroups comp.lang.python
Subject Re: Let exception fire or return None
Organization Decebal Computing
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Date Thu, 30 Apr 2015 14:22:08 +0200
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Op Thursday 30 Apr 2015 13:26 CEST schreef Cecil Westerhof:

>> try:
>> [line] = itertools.islice(f, index, index+1)
>> except ValueError:
>> raise IndexError
>> return line.rstrip()
>
> In my case it is not important. (The biggest file I use has between
> 100 and 200 lines), but I publish it, so I should do my best to make
> it so lean as possible.

Implemented and pushed to:
    https://github.com/CecilWesterhof/PythonLibrary/blob/master/filebasedMessages.py

Did some other optimisation's also. The function get_random_message
now calls get_indexed_message. Saves memory (on the old
implementation) and is more DRY.

I also enhanced get_nr_of_messages:
    def get_nr_of_messages(message_filename):
        i = -1
        with open(expanduser(message_filename), 'r') as f:
            for i, l in enumerate(f):
                pass
        return i + 1

Or can that be done better?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

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Thread

Let exception fire or return None Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 09:43 +0200
  Re: Let exception fire or return None Dave Angel <davea@davea.name> - 2015-04-30 04:18 -0400
    Re: Let exception fire or return None Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 11:13 +0200
  Re: Let exception fire or return None Peter Otten <__peter__@web.de> - 2015-04-30 11:30 +0200
    Re: Let exception fire or return None Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 13:26 +0200
      Re: Let exception fire or return None Peter Otten <__peter__@web.de> - 2015-04-30 14:28 +0200
        Re: Let exception fire or return None Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 16:53 +0200
      Re: Let exception fire or return None Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 14:22 +0200
  Re: Let exception fire or return None Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-04-30 14:05 +0200
  Re: Let exception fire or return None Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-04-30 14:30 +0200

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