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There are bugs and then there are bugs. And then there are bugs. -- Karl Lehenbauer

Re: tail

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https://www.novabbs.com/devel/article-flat.php?id=18318&group=comp.lang.python#18318

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From: Marco.Su...@gmail.com (Marco Sulla)
Newsgroups: comp.lang.python
Subject: Re: tail
Date: Tue, 17 May 2022 22:45:34 +0200
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by: Marco Sulla - Tue, 17 May 2022 20:45 UTC

Well, I've done a benchmark.

>>> timeit.timeit("tail('/home/marco/small.txt')", globals={"tail":tail}, number=100000)
1.5963431186974049
>>> timeit.timeit("tail('/home/marco/lorem.txt')", globals={"tail":tail}, number=100000)
2.5240604374557734
>>> timeit.timeit("tail('/home/marco/lorem.txt', chunk_size=1000)", globals={"tail":tail}, number=100000)
1.8944984432309866

small.txt is a text file of 1.3 KB. lorem.txt is a lorem ipsum of 1.2
GB. It seems the performance is good, thanks to the chunk suggestion.

But the time of Linux tail surprise me:

marco@buzz:~$ time tail lorem.txt
[text]

real 0m0.004s
user 0m0.003s
sys 0m0.001s

It's strange that it's so slow. I thought it was because it decodes
and print the result, but I timed

timeit.timeit("print(tail('/home/marco/lorem.txt').decode('utf-8'))",
globals={"tail":tail}, number=100000)

and I got ~36 seconds. It seems quite strange to me. Maybe I got the
benchmarks wrong at some point?

There are bugs and then there are bugs. And then there are bugs. -- Karl Lehenbauer

devel / comp.lang.python / Re: tail