From: William James <w_a_x_man@...>
Date: 2006-12-28T15:35:08+09:00
Subject: Re: Need help massaging some strings

Taylor Strait wrote:
> As a Rails developer, I've been learning Ruby on a need-to-know basis.
> However, I now need to tap its power to batch alter some very large text
> dumps and find myself a bit lost.  Here is what I need to do:
>
> Transform data in files like "alabama.txt":
>     * White Hall, Lowndes County
>     * Wilmer, Mobile County
>     * Wilsonville, Shelby County
>     * Wilton, Shelby County
>     * Winfield, Marion County
>     * Winterboro, Talladega County
>
> ..into this format:
> White Hall
> Wilmer
> Wilsonville
> Wilton
> Winfield
> Winterboro
>
> I have created a method for doing this in "cleanup.rb":
>
> def cleanup(state)
>   diskfile = File.new(state + "-cleaned.txt", "w")
>   $stdout = diskfile
>
>   IO.foreach(state + ".txt") do |line|
>     line.delete("\*")
>     line.strip!
>     temp = line.split(",")
>     temp.delete_at(1).to_s
>     puts temp
>   end
>
>   diskfile.close
>   $stdout = STDOUT
> end
>
> So I go into IRB and here is how my session goes:
>
> irb(main):008:0> require 'cleanup'
>   => true
> irb(main):009:0> cleanup(alabama)
>   NameError: undefined local variable or method `alabama' for
> main:Object
> irb(main):010:0> cleanup
>   ArgumentError: wrong number of arguments (0 for 1)

def cleanup(state)
  File.open(state + "-cleaned.txt", "w") do |outfile|
    IO.foreach(state + ".txt") do |line|
      outfile.puts line[ /^[\s*]*(.*),[^,]*$/, 1 ]
    end
  end
end

Or:

def cleanup(state)
  File.open(state + "-cleaned.txt", "w") { |out|
    out.puts IO.readlines(state + ".txt").map{|line|
      line[ /^[\s*]*(.*),[^,]*$/, 1 ] } }
end

Or even:

def cleanup(s)
  open(s+"-cleaned.txt","w"){|o|o<<IO.read(s+".txt").
    gsub(/^[ *]*|,.*$/,"")}
end