Tab-separated parsing using Ruby 2.0 CSV library

strict_tsv.rb

# The main parse method is mostly borrowed from a tweet by @JEG2
class StrictTsv
  attr_reader :filepath
  def initialize(filepath)
    @filepath = filepath
  end

  def parse
    open(filepath) do |f|
      headers = f.gets.strip.split("\t")
      f.each do |line|
        fields = Hash[headers.zip(line.split("\t"))]
        yield fields
      end
    end
  end
end

strict_tsv_example.rb

tsv = Vendor::StrictTsv.new("your_file.tsv")
tsv.parse do |row|
  puts row['named field']
end

tsv_example.rb

require 'csv'
line = 'boogie\ttime\tis "now"'
begin
  line = CSV.parse_line(line, col_sep: "\t")
  puts "parsed correctly"
rescue CSV::MalformedCSVError
  puts "failed to parse line"
end

begin
  line = CSV.parse_line(line, col_sep: "\t", quote_char: "Ƃ")
  puts "parsed correctly with random quote char"
rescue CSV::MalformedCSVError
  puts "failed to parse line with random quote char"
end

#Output:
# failed to parse line
# parsed correctly with random quote char

I found that on line 11 of tsv_example.rb I actually have to use something like quote_char: "\u02f6" rather than a literal weird character or ruby complains about an unexpected $end at that location... I don't understand why, but it works.

Line 12 of strict_tsv.rb needs to use line.strip.split to remove the line terminator from the last column in each row.

Having a need to parse a huge file and inspired by this snippet, we've written a bit more complex solution, with ability to switch headers on or off and access rows in both array- and hash-like way. I'd appreciate if you could take a look at it and possibly provide feedback.

Thanks,
Slotos

@Slotos your gem looks really helpful. I'm glad to have contributed in some way to it.