Shortest Codes

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January 17th, 2013, 06:10 PM

sandra8989

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Shortest Codes

what is the shortest way to write a python code to open a file and print the length of the longest line in the file?

January 17th, 2013, 10:00 PM

b49P23TIvg

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Target practice

Here are "one liner" solutions in 3 languages. They all read stdin. jconsole from www.jsoftware.com

Code:

$ alias jc=/usr/local/j64-701/bin/jconsole

$ jc      -js 'exit echo#{.[;._2[1!:1<3'
$ gawk    '{b=length;a=a>b?a:b}END{print a}'
> python3 -c 'print(max(map(len,open("con:")))-1)'
$ python3 -c 'print(max(map(len,open("/dev/fd/0")))-1)'  # map by Nyktos
$ python3 -c 'print(max(len(L)for L in open("/dev/fd/0"))-1)'  # /dev/fd/0, no readlines by Lux Perpetua

python2 could be one character shorter. Puzzle remains open. (I assume those of you who know the answer are nice enough to not tell.)

I've assumed the last line ends with a new line character, and that there's at least one line.

Code:

$ python3 -c 'import sys;print(max(len(L)for L in sys.stdin.readlines())-1)'  # original python solution

These are some targets for you all to beat.

__________________
[code]Code tags[/code] are essential for python code!

Last edited by b49P23TIvg : January 21st, 2013 at 05:12 PM. Reason: Restate 1st python solution

January 18th, 2013, 09:31 PM

b49P23TIvg

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New python3 solution in unix! 2 characters shorter.

January 19th, 2013, 01:08 AM

Lux Perpetua

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Continuing your train of thought:

Code:

$ python3 -c 'print(max(len(L)for L in open("/dev/fd/0"))-1)'

Last edited by Lux Perpetua : January 19th, 2013 at 01:10 AM.

January 19th, 2013, 08:25 AM

b49P23TIvg

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"best" python solution reduced!

January 19th, 2013, 05:47 PM

Nyktos

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You can use map in place of the generator expression to shorten it further:

Code:

print(max(map(len,open("con:")))-1)
print(max(map(len,open("/dev/fd/0")))-1)

Comments on this post

Dietrich agrees: nice thinking

January 19th, 2013, 07:24 PM

b49P23TIvg

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Opening a specific file, as a different interpretation of the problem statement:

Code:

$ alias jc=/usr/local/j64-701/bin/jconsole # www.jsoftware.com

$ jc      -js "exit echo#{.[;._2 fread'filename'"
$ gawk    '{b=length;a=a>b?a:b}END{print a}' filename
$ python2 -c 'print max(map(len,open("filename")))-1'
$ python3 -c 'print(max(map(len,open("filename")))-1)'

Whoot! Found an historical feature of gawk.
Whoot! Improved the j code.

Last edited by b49P23TIvg : January 21st, 2013 at 05:19 PM.

January 21st, 2013, 05:17 PM

b49P23TIvg

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Shortened j sentence with monadic cut.

Last edited by b49P23TIvg : January 21st, 2013 at 05:22 PM.

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