That history meme, in Python!

It seemsed that everyone was joining in the 'history meme', and finding
out what was in their history:

href="http://blogs.gnome.org/newren/2008/04/11/that-history-meme/">http://blogs.gnome.org/newren/2008/04/11/that-history-meme/

href="http://jaysonrowe.wordpress.com/2008/04/11/command-history-meme/">http://jaysonrowe.wordpress.com/2008/04/11/command-history-meme/

href="http://jjesse.wordpress.com/2008/04/11/joining-the-history-meme/">http://jjesse.wordpress.com/2008/04/11/joining-the-history-meme/

href="http://fengshaun.wordpress.com/2008/04/11/shell-history-meme/">http://fengshaun.wordpress.com/2008/04/11/shell-history-meme/

(You get the idea, ... more href="http://blogsearch.google.co.uk/blogsearch?hl=en&ie=UTF-8&q=%22history+meme%22&btnG=Search+Blogs">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|head

This 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;  style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">    pprint.pprint(sorted style="font-weight: bold; color: rgb(0, 0, 153);">([ style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">        (len(list(g)),k) for k,g in itertools.groupby(sorted style="font-weight: bold; color: rgb(153, 51, 153);">([
            x.split()[1]for x in sys.stdin if len(x.split())>1 style="font-weight: bold; color: rgb(153, 51, 153);">])
            , lambda x:x) style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">         style="font-weight: bold; color: rgb(0, 0, 153);">]) style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">        [-10:][::-1])'  style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">[(63, 'echo'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (41, 'history'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (30, './tst1.sh'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (28, 'declare'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (21, 'python'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (18, 'perl'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (18, 'cat'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (16, 'ls'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (15, 'xterm'), style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;"> (15, 'history|python')] style="font-family: Courier New,Courier,monospace;"> style="font-family: Courier New,Courier,monospace;">bash$ 

I decided to break the command into multiple lines for readability
above; it was developed, painfully, all on one line.



So readers, the above is something that Python stinks at - one-liners.
(Unless you know a better way in Python ...)



- Paddy.