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copied!<p>CSV supports "converters" for the <a href="http://ruby-doc.org/stdlib-1.9.3/libdoc/csv/rdoc/CSV.html#method-i-header_convert" rel="nofollow">headers</a> and <a href="http://ruby-doc.org/stdlib-1.9.3/libdoc/csv/rdoc/CSV.html#method-i-convert" rel="nofollow">fields</a>, which let you get inside the data before it's passed to your <code>each</code> loop. </p> <p>Writing a sample CSV file:</p> <pre><code>csv = "First,Last,Email ,Mobile Phone ,Company,Title ,Street,City,State,Zip,Country, Birthday,Gender ,Contact Type first,last,email ,mobile phone ,company,title ,street,city,state,zip,country, birthday,gender ,contact type " File.write('file_upload_example.csv', csv) </code></pre> <p>Here's how I'd do it:</p> <pre><code>require 'csv' csv = CSV.open('file_upload_example.csv', :headers => true) [:convert, :header_convert].each { |c| csv.send(c) { |f| f.strip } } csv.each do |row| puts "First Name: #{row['First']} \nLast Name: #{row['Last']} \nEmail: #{row['Email']}" end </code></pre> <p>Which outputs:</p> <pre><code>First Name: 'first' Last Name: 'last' Email: 'email' </code></pre> <p>The converters simply strip leading and trailing whitespace from each header and each field as they're read from the file.</p> <p>Also, as a programming design choice, don't read your file into memory using:</p> <pre><code>csv_text = File.read('file_upload_example.csv') </code></pre> <p>Then parse it:</p> <pre><code>csv = CSV.parse(csv_text, :headers => true) </code></pre> <p>Then loop over it:</p> <pre><code>csv.each do |row| </code></pre> <p>Ruby's IO system supports "enumerating" over a file, line by line. Once my code does <code>CSV.open</code> the file is readable and the <code>each</code> reads each line. The entire file doesn't need to be in memory at once, which isn't scalable (though on new machines it's becoming a lot more reasonable), and, if you test, you'll find that reading a file using <code>each</code> is extremely fast, probably equally fast as reading it, parsing it then iterating over the parsed file.</p>

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