I want to write header only 1 time in first row when import data to csv in ruby, but the header is written many time on output file.
job_datas.each do |job_data|
#company_job = job data coverted etc....
save_job_to_csv(#company_job)
end
def save_job_to_csv(job_data)
filepath = "tmp/jobs/jobs.csv"
CSV.open(filepath, "a", :headers => true) do |csv|
if csv.blank?
csv << CompanyJob.attribute_names
end
csv << job_data.attributes.values
end
end
Any one can give me solution? Thank you so much!
You are calling save_job_to_csv the method for each job_data and pushing header every time csv << CompanyJob.attribute_names
filepath = "tmp/jobs/jobs.csv"
CSV.open(filepath, "a", :headers => true) do |csv|
# push header once
csv << CompanyJob.attribute_names
# push every job record
job_datas.each do |job_data|
#company_job = job data coverted etc....
csv << #company_job.attributes.values
end
end
The above script can be created wrapped a method but if you like to write a separate method that just saves the CSV, then you need to refactor the script when you first prepare an array of values holding header and pass it to a method that just saves to CSV.
You could do something similar to this:
def save_job_to_csv(job_data)
filepath = "tmp/jobs/jobs.csv"
unless File.file?(filepath)
File.open(filepath, 'w') do |file|
file.puts(job_data.attribute_names.join(','))
end
end
CSV.open(filepath, "a", :headers => true) do |csv|
csv << job_data.attributes.values
end
end
It just checks beforehand if the file exists and if not it adds the header. If you want tabs as column separators, you just have to change the value for the join function and add the col_sep parameter to CSV.open():
file.puts(job_data.attribute_names.join("\t"))
CSV.open(filepath, "a", :headers => true, col_sep: "\t") do |csv|
I'm new to rails and am trying to process a CSV file, some files will have comments at the start of the CSV file, comments are marked with #. If there a way I can delete these rows? I don't have to just ignore them as I want to save the file without comments.
sample file:
#-----------------------
# report --------------
#-----------------------
Date, transctions
20100923, 34
20200110, 56
Thanks.
The CSV library has a skip_lines options:
When setting an object responding to match, every line matching it is considered a comment and ignored during parsing. When set to a String, it is first converted to a Regexp. When set to nil no line is considered a comment. If the passed object does not respond to match, ArgumentError is thrown.
This should work for you:
CSV.foreach(file, skip_lines: /^#/, headers: true) do |row|
# ...
end
/^#/ matches lines starting with #.
Adding something to #Stefan answer (all credit goes to him for the skip_lines tip), assuming your csv file is input.csv :
require "csv"
CSV.open("output.csv", "wb") do |output_csv|
CSV.foreach("input.csv", skip_lines: /^#/, headers: true) do |row|
# ...
output_csv << row
end
end
This way you will end with a file output.csv without those comments.
EDIT:
If you want also the header, you can do:
CSV.open("output.csv", "wb") do |output_csv|
CSV.foreach("input.csv", skip_lines: /^#/, headers: true).with_index(0) do |row, i|
output_csv << row.headers if i == 0
puts row
output_csv << row
end
end
...It's not as clean as I want but fits your needs ;)
I am running a transaction download script through Ruby. I was wondering if it is possible to label each .csv it creates with the current date/time the script was run. Below is the end of the script.
CSV.open("transaction_report.csv", "w") do |csv|
csv << header_row
search_results.each do |transaction|
transaction_details_row = header_row.map{ |attribute| transaction.send(attribute) }
csv << transaction_details_row
end
end
Like this?
CSV.open("transaction_report-#{Time.now}.csv", "w") do |csv|
csv << header_row
search_results.each do |transaction|
transaction_details_row = header_row.map{ |attribute| transaction.send(attribute) }
csv << transaction_details_row
end
end
This just appends the time of generation to the file name. For example:
"transaction_report-#{Time.now}.csv"
# => "transaction_report-2019-10-10 16:09:07 +0100.csv"
If you want to avoid spaces in the file name, you can sub these out like so:
"transaction_report-#{Time.now.to_s.gsub(/\s/, '-')}.csv"
# => "transaction_report-2019-10-10-16:09:40-+0100.csv"
Is that what you're after? It sounds right based on the question, though happy to update if you're able to correct me :)
Ruby 2.2, Ruby on Rails 4.2
I'm genarating some CSV data in Ruby on Rails, and want empty fields to be empty, like ,, not like ,"", .
I wrote codes like below:
somethings_cotroller.rb
def get_data
respond_to do |format|
format.html
format.csv do
#data = SheetRepository.accounts_data
send_data render_to_string, type: :csv
end
end
end
somethings/get_data.csv.ruby
require 'csv'
csv_str = CSV.generate do |csv|
csv << [1,260,37335,'','','','','','']
...
end
And this generates CSV file like this.
get_data.csv
1,260,37335,"","","","","",""
I want CSV data like below.
1,260,37335,,,,,,
It seems like Ruby adds "" automatically.
How can I do this??
In order to get CSV to output an empty column, you need to tell it that nothing is in the column. An empty string, in ruby, is still something, you'll need to replace those empty strings with nil in order to get the output you want:
csv_str = CSV.generate do |csv|
csv << [1,260,37335,'','','','','',''].map do |col|
col.respond_to?(:empty?) && col.empty? ? nil : col
end
end
# => 1,260,37335,,,,,,
In rails you can clean that up by making use of presence, though this will blank out false as well:
csv_str = CSV.generate do |csv|
csv << [1,260,37335,'',false, nil,'','',''].map(&:presence)
end
# => 1,260,37335,,,,,,
The CSV documentation shows an option that you can use for this case. There are not examples but you can guess what it does.
The only consideration is, you need to send an array of Strings, otherwise, you will get a NoMethodError
csv_str = CSV.generate(write_empty_value: nil) do |csv|
csv << [1,260,37335,'','','','','','', false, ' ', nil].map(&:to_s)
end
=> "1,260,37335,,,,,,,false, ,\n"
The benefit of this solution is, you preserve the false.
I resolved by myself!
in somethings_controller.rb
send_data render_to_string.gsub("\"\"",""), type: :csv
In rails 4.2.4, I am trying to extract the data from .csv file and save it to the database. But right now extracted row from the file is in wrong format so that value is not getting save.
require 'csv'
filename = "#{asset.document.path}"
if File.exist?(filename)
file = File.open(filename)
if file
CSV::parse(file)[1..-1].each do |row|
User.create_data(row, admin)
end
end
end
def create_data(row, admin)
usr = User.new
usr.name = row[0] if row[0]
usr.email = row[1] if row[1]
usr.password = row[2] if row[2]
user.save
end
Generated row's data is like ["Sannidhi\tsannidhi#gmail.com\tsannidhi123#\t"]. From this row I am not getting each values separately Eg: row[0], row[1] & row[2] to assign for related database fields.
How can I solve this CSV import issue? Please help me.
Try this:
CSV::parse(file)[1..-1].each do |row|
row.shift.split("\t") unless row.blank?
User.create_data(row, admin)
end
After this, you should be able to access:
row[0] #=> "Sannidhi"
row[1]
row[2]
You CSV file uses tabs as column separators. You can pass your own column separator to CSV as a col_sep option. Even though other 2 answers will do the job, let csv do its job on its own:
CSV::parse(file, col_sep: "\t")[1..-1].each do |row|
User.create_data(row, admin)
end
Also, consider using headers option to use the first line of the file as a header instead of [1..-1]:
CSV::parse(file, col_sep: "\t", headers: 'first_row').each do |row|
User.create_data(row, admin)
end
CSV stands for Comma Separated Value. It seems that your file is separated by spaces instead. Replace the tabs in your file by commas.