http://blogs.gnome.org/newren/2008/04/11/that-history-meme/
http://jaysonrowe.wordpress.com/2008/04/11/command-history-meme/
http://jjesse.wordpress.com/2008/04/11/joining-the-history-meme/
http://fengshaun.wordpress.com/2008/04/11/shell-history-meme/
(You get the idea, ... more here).
http://jaysonrowe.wordpress.com/2008/04/11/command-history-meme/
http://jjesse.wordpress.com/2008/04/11/joining-the-history-meme/
http://fengshaun.wordpress.com/2008/04/11/shell-history-meme/
(You get the idea, ... more here).
They were all using unix command line tools, piped together to show the most frequent commands they had used.:
history|awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}'|sort -rn|headThis being a Python blog, and knowing before-hand that Python is really awful at one-liners, I nevertheless decided that it would be of some use to try and pipe history to a Python one-liner that performed a similar task .
I came up with:
bash$ history | python -c 'import sys,itertools,pprint;
pprint.pprint(sorted([
(len(list(g)),k) for k,g in itertools.groupby(sorted([
x.split()[1]for x in sys.stdin if len(x.split())>1])
, lambda x:x)
])
[-10:][::-1])'
[(63, 'echo'),
(41, 'history'),
(30, './tst1.sh'),
(28, 'declare'),
(21, 'python'),
(18, 'perl'),
(18, 'cat'),
(16, 'ls'),
(15, 'xterm'),
(15, 'history|python')]
bash$
So readers, the above is something that Python stinks at - one-liners. (Unless you know a better way in Python ...)
- Paddy.
6 comments:
You don't need the "lambda x:x". itertools.groupby defaults to the identity function for the key. That makes it a bit shorter!
You might like my pyline script, which I wrote to make Python work well in command pipelines. I use it all the time, and it's one of the first things I install on a new Unix box.
Hi David,
Someone actually read that god-awful mess that I wrote - to such a degree that they understood it?!?!
Thanks for correction. I had not known that about groupby. (I have gone from reading about it and thinking that I will never use it - it must be there for completeness sake, to using groupby several times).
Hi fawcett,
I had seen pyline before but my post was just to show Pythons limitations. I do know my way around standard Unix tools, as well as Perl and AWK and tend to use them for my huge one-liners :-)
- Paddy.
P.S.
The two list comprehensions could be replaced by generator expressions but they stayed as it was easier to find my way around the line with the occasional ']' or '[' to 'anchor' me when reading the mush.
- Paddy.
python isn't that bad, if you have helper modules lying around...
history | python -c 'import sys,pprint,count;
pprint.pprint(count.count(x.split()[1] for x in sys.stdin)[:10])'
works for me :)
Hi Justin,
You just got me scrambling off searching for this unknown count module - which turns out to not be a standard module, which I guess is your point.
No pulling magic bunnies out of a hat! :-)
- Paddy.
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