How to skip the first line of a CSV file and make the second line the header

Question

Is there a way to skip the first line of a CSV file and make the second line act as the header?

I have a CSV file that has the date on the first row and the headers

Answer 1

You can do this

text = File.readlines("file.csv")[1..-1].join()
csv = CSV.parse(text, headers: true)

Answer 2

Depending on your data you may use another approach with theskip_lines-option

This examples skip all lines with a leading #

require 'csv'

CSV.parse(DATA.read,:col_sep=>';',:headers=>true,
    :skip_lines=> /^#/  #Mark comments!
  ) do |row|
  p row
end
#~ 
__END__
#~ Comment
#~ More comment
a;b;c;d
1;2;3;4
#~ More comment
1;2;3;4
#~ More comment
1;2;3;4

The result is

#<CSV::Row "a":"1" "b":"2" "c":"3" "d":"4">
#<CSV::Row "a":"1" "b":"2" "c":"3" "d":"4">
#<CSV::Row "a":"1" "b":"2" "c":"3" "d":"4">

In your case the csv contains a date, so you may use:

require 'csv'

CSV.parse(DATA.read,:col_sep=>';',:headers=>true,
    :skip_lines=> /^\d\d\d\d-\d\d-\d\d$/  #Skip line with date only
  ) do |row|
  p row
end
#~ 
__END__
2016-03-19
a;b;c;d
1;2;3;4
1;2;3;4
1;2;3;4

or you could use more extend starting lines:

require 'csv'

CSV.parse(DATA.read,:col_sep=>';',:headers=>true,
    :skip_lines=> /^Created by/  #Skip line with date only
  ) do |row|
  p row
end

__END__
Created by test.rb on 2016-03-19
a;b;c;d
1;2;3;4
1;2;3;4
1;2;3;4

Answer 3

This simple code worked for me. You can read a CSV file and ignore its first line which is the header or field names:

CSV.foreach(File.join(File.dirname(__FILE__), filepath), headers: true) do |row|
    puts row.inspect
end

You can do what ever you want with row. Don't forget to use headers: true

Answer 4

I had the same problem (except I wanted to skip more than 1 line at the beginning) and came across this question while looking for a nice solution. For my case, I went with the code described in this answer to a similar question, except that I am also utilizing the headers option as you mentioned you wanted to do.

CSV.parse(File.readlines(path).drop(1).join, headers: true) do |row|
  # ... now I can use: row['column_name']
end

Answer 5

I don't think there's an elegant way of doing it, but it can be done:

require "csv"

# Create a stream using the original file.
# Don't use `textmode` since it generates a problem when using this approach.
file = File.open "file.csv"

# Consume the first CSV row.
# `\r` is my row separator character. Verify your file to see if it's the same one.
loop { break if file.readchar == "\r" }

# Create your CSV object using the remainder of the stream.
csv = CSV.new file, headers: true