From: Hugh Sasse <hgs@...>
Date: 2008-10-28T09:56:23+09:00
Subject: Re: String Comparison Problems



On Tue, 28 Oct 2008, mdrisser wrote:

> Hi All,
> 
> I'm having a baffling problem with string comparisons in Ruby.
> 
> The following code just does not act as expected.
> measures_full = {'PROP 1A'=>'Safe, Reliable High-Speed Train Bond
> Act',
>                 'PROP 2' =>'Standards for Confining Farm Animals',
        [...]
>                 'PROP 11'=>'Redistricting',
>                 'PROP 12'=>"Veterans' Bond"}
> fixed_ca = Array.new
> prop = String.new
> lines = Array.new
> i = 1;
> j = 0;
> 
> puts ''
> puts "-----------------------READING------------------------"
> # Add prop numbers to props for CA feed
> open('2008-CA_ElectionResults.csv', 'r') do |f|
>   line = f.read
>   lines = line.split("\n") # Not really sure why this is necessary,
>                            # but for some reason its the only way to
>                            # get each line into its own place in the
> array.

# Or your could use readlines instead, which would give you the array 
# straight away.  Your data looks simple enough for the CSV library
# (or FasterCSV if you need speed) to handle this.
>   j += 1
>   #puts j
> end
> 
> puts "#{lines.length} entries"
> 
> lines.each do |line|
>   vals = line.split('|')
> 
>   measures_full.each do |key, value|
      # It might be instructive to :
      puts value.dump
      puts vals[0].dump
      # or  puts " #}value.dump} #{vals[0].dump}" if you prefer.

>     if value.eql? vals[0]

------------------------------------------------------------ Hash#select
     hsh.select {|key, value| block}   => array
------------------------------------------------------------------------
     Returns a new array consisting of +[key,value]+ pairs for which the
     block returns true. Also see +Hash.values_at+.

        h = { "a" => 100, "b" => 200, "c" => 300 }
        h.select {|k,v| k > "a"}  #=> [["b", 200], ["c", 300]]
        h.select {|k,v| v < 200}  #=> [["a", 100]]


>       puts vals[0]

>       prop = "#{key} - #{value}|#{vals[1]}|#{vals[2]}|#{vals[3]}|
> #{vals[4]}|#{vals[5]}|#{vals[6]}|#{vals[7]}|#{vals[8]}|#{vals[9]}"
>       puts prop
>       break
>     else
>       prop = line
>       break
>     end
>   end
>   #puts prop
>   fixed_ca << prop
>   i = i + 1
> end
> 
> puts ''
> puts "-----------------------WRITING------------------------"
> open('2008-CA_Fixed.csv', 'w') do |f|
>   fixed_ca.each do |e|
>     f.puts e
>   end
> end
> 
> The file I'm opening contains:
> U.S. President|0|0||Barack Obama|Democratic|9075132|58.1|09/24/2008|
> 12:38:04
        [...]
> State Assembly District 75|0|0||Nathan Fletcher|Republican|808|0.3|
> 09/24/2008|12:38:04
> State Assembly District 75|0|0||John Murphy|Libertarian|15359|6.6|
> 09/24/2008|12:38:04

And there's nothing here to mark the change in data? No count at the
start of the file?

> Standards for Confining Farm Animals|0|0||Yes||5200770|6.6|09/24/2008|
> 12:38:04
> Standards for Confining Farm Animals|0|0||No||10439300|6.6|09/24/2008|
> 12:38:04
        [...]
> Altern. Fuel Vehicles and Renewable Energy Bonds|0|0||No||9535744|6.6|
> 09/24/2008|12:38:04
> Redistricting|0|0||Yes||10740910|6.6|09/24/2008|12:38:04
> Redistricting|0|0||No||4899160|6.6|09/24/2008|12:38:04
> Veterans' Bond|0|0||Yes||5284610|6.6|09/24/2008|12:38:04
> Veterans' Bond|0|0||No||10355460|6.6|09/24/2008|12:38:04
> 
> I *SHOULD* be getting 24 matches, but for some reason I'm only getting
> 2 and those are for measure_full['PROP 11']. I've even gone so far as
> to copy and paste the values from the CSV file into the corresponding
> places in the Hash, but it makes no difference, only
> measure_full['PROP 11'] matches as expected.
> 
        Hugh