Let exception fire or return None
Cecil at decebal.nl
Thu Apr 30 16:53:43 CEST 2015
Op Thursday 30 Apr 2015 14:28 CEST schreef Peter Otten:
> Cecil Westerhof wrote:
>>> (2) you may want to take measures to limit memory usage, e. g.
>>> assert index >= 0
>> I put that in, but as first statement.
> For the record, this was not a recommended check, but rather a way
> to communicate to the reader of my code that unlike yours it doesn't
> support negative indices.
>>> [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.
> If you keep your
> return f.readlines()[index]
> anyway you might allow for negative indices, and then
> get_indexed_message(message_filename, -1)
> fetches the last message in the file and
> get_indexed_message(message_filename, slice(None, None))
> fetches a list with all messages.
It is even possible without keeping it. I can fetch the number of
messages and implement it myself without a possible high memory
overhead. Certainly something to think about.
Senior Software Engineer
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