From: ES <ruby-ml@...>
Date: 2005-10-12T05:16:18+09:00
Subject: Re: Ruby noob with a coming from Python question

Jeff Carlson wrote:
> I am very new to ruby and thought I would start with my simplest python 
> script and port it over and along the way, learn the "ruby way" of doing 
> things.  My solution so far is unsatisfactory and long.  If you have any 
> suggestions, most especially about the "ruby way" to write the file2Map 
> method, I would appreciate it and all of my future ruby programs would 
> also appreciate it.
> 
> Cheers,
> Jeff Carlson
> 
> -------------------------------------------------------------
> #!/usr/bin/python
> # print statistics for seti@home jobs
> from mx.DateTime import TimeDelta
> import sys
> 
> # this method takes a file with key/value pairs, seperated by "="
> # and makes a map of the file, keys and values, the length of the
> # map is the length of the file
> def getMapFromFile(fname):
>     lines = open(fname).readlines()
>         return dict([line.split("=") for line in lines])

This should work:

def map_from(file)
   Hash[*File.readlines(file).map {|line| line.split '='}.flatten]
end

Broken down, File.readlines makes an Array of lines in the file; we
then #map it to split each line into the two parts and then #flatten
the Array from [[key1, val1], [key2, val2]] to [key1, val1, key2, val2].

This syntax can be used by Hash[], so we just 'splat' the Array
to individual values by using the * operator.

> # make maps of the two files
> sMap = getMapFromFile(sys.argv[1])
> uMap = getMapFromFile(sys.argv[2])
> 
> prog = float(sMap["prog"].strip())*100
> et = TimeDelta(seconds=float(sMap["cpu"].strip()))
> 
> #print results
> print '%.2f%c completed in %d:%02d:%02d' % (prog, '%', et.hour, /
>     et.minute, et.second)
> print 'units of work so far %s' % (uMap["nresults"].strip())

E