I generate a CSV text file in Rails like this:
CSV.generate(col_sep: ';') do |csv|
sheet.add_row ['1st line']
sheet.add_row ['2nd line']
end
When I open the text file the two lines are there as expected. Unfortunately this file now should be used by a program that reads the file and I get an error message, that the second line is missing. I have a sample file that looks exactly like the file I generated which works fine but my file can't be read properly. It also has the same encoding. Any suggestions where to look? Anything concerning line breaks?
I'm not sure this is a question that can be answered as asked. You said that a 3rd party program is having trouble reading a text file generated by Ruby, but provided no information on that error and how you think Ruby is related to this error.
Could you please update your original post with the plaintext version of your CSV file and what program you're trying to open it in?
Related
I'm working on a project with some supplied CSV files that I need to parse and do some manipulation on. One is throwing this error when I try to load it into a file using CSV.read('path/file.csv')
CSV::MalformedCSVError: Unquoted fields do not allow \r or \n (line 7911).
Now when looking at the file, the last line is just blank. It's a \n character. I feel like this should not break the CSV read but it is. Now, I could just check the end of the CSV documents and strip any access return carriages/new lines since that seems like it'll work but it doesn't seem like the correct way. Anybody have some advice?
Edit: Using Ruby 2.0.0 and Rails 4.0.5
I have a .xlsx file converted to .csv.I need to write a script to modify this file(change/rename columns etc.) How can I open this .csv file and save it from within the script?
Thanks!
Open the csv file just like you would open any other file in ruby using the standard File api
csv_file = File.open('data.csv', 'r')
Parse it manually or use a library like FasterCSV. Make your modifications, writeback to the file and close. There is nothing inherently special about a csv file, work with it like you would with any file in ruby.
You should proably work with a CSV library (or in the ruby world a gem). So install the gem,
and your code will look something like this:
FasterCSV.foreach("path/to/file.csv") do |row|
# use row here...
end
http://fastercsv.rubyforge.org/
As far as I know, you cannot make inline modifications to the CSV file. You would have to output via another file.
I am trying to parse a CSV file generated from an Excel spreadsheet.
Here is my code
require 'csv'
file = File.open("input_file")
csv = CSV.parse(file)
But I get this error
ArgumentError: invalid byte sequence in UTF-8
I think the error is because Excel encodes the file into ISO 8859-1 (Latin-1) and not in UTF-8
Can someone help me with a workaround for this issue, please
Thanks in advance.
You need to tell Ruby that the file is in ISO-8859-1. Change your file open line to this:
file=File.open("input_file", "r:ISO-8859-1")
The second argument tells Ruby to open read only with the encoding ISO-8859-1.
Specify the encoding with encoding option:
CSV.foreach(file.path, headers: true, encoding:'iso-8859-1:utf-8') do |row|
...
end
You can supply source encoding straight in the file mode parameter:
CSV.foreach( "file.csv", "r:windows-1250" ) do |row|
<your code>
end
If you have only one (or few) file, so when its not needed to automatically declare encoding on whatever file you get from input, and you have the contents of this file visible in plaintext (txt, csv etc) separated with i.e. semicolon, you can create new file with .csv extension manually, and paste the contents of your file there, then parse the contents like usual.
Keep in mind, that this is a workaround, but in need of parsing in linux only one big excel file, converted to some flavour of csv, it spares time on experimenting with all those fancy encodings
Save the file in utf-8, unless for some reason you need to save it differently in which case you may specify the encoded set while reading the file
add second argument "r:ISO-8859-1" as File.open("input_file","r:ISO-8859-1" )
I had this same problem and was just using google spreadsheets and then downloading as a CSV. That was the easiest solution.
Then I came across this gem
https://github.com/singlebrook/utf8-cleaner
Now I don't need to worry about this issue at all. Hope this helps!
I am trying to upload a file in rails (using paperclip), and I want to process some of the file data before letting paperclip send it off to s3 storage. In my controller, I just grab the file parameter (which does give me a file) and then I try to read the lines into an array
csv_file = params[:activity][:data]
array = IO.readlines(csv_file.path)
The problem is, I'm only getting the last line of the file. I tried using .rewind, but still get just the last line.
I dislike readlines and I always use regular expressions. Try this.
End of line - \n
Handy block structure to ensure that the file handle is closed:
File.open(csv_file.path) do |f|
a = f.readlines
process a...
end
Reading a whole file into memory might not be a good idea depending on the size of the files.
Issues reading CSV file using OLEDB when filename have period.
I have a code in C# that reads CSV File using OleDBProvider. It works perfect with filenames in regular format such as Budget.csv but failed when i renamed the file into Budget.DKK.csv or Budget.USD.csv
I throws this exception:
he Microsoft Jet database engine could not find the object 'Budget.DKK.csv'. Make sure the object exists and that you spell its name and the path name correctly.
I have no idea so far why is this happening.
If this thread is to be believed, then it is a known problem that won't be fixed. It mentions a work-around that allows the name to be forced into the old style 8.3 format.
And just as a random suggestion if you haven't tried it, maybe delimit the filename with brackets [filename.stuff.txt]. I doubt it is that simple, though.