[code] reading a CSV file

Dan Rathbun

Here's an example by Jim Foltz (he posted in GoogleGroups - Sketchup Developers),
but modified, module and method wrapped.

I (Dan) also added:

flexibility for a header row* setting a value delimiter in the method call.

Returning CSV data as an Array of record Arrays

Feel free to change the methodname to suit your taste.


module MyTopLevelNamespace  #<--- you change this
  module MyPlugin           #<--- you change this also
    class<<self

      def read_csv_to_array(file,
                            relapath='.',
                            basepath=Dir.getwd,
                            delim=',',
                            header=false)
        firstline=true
        data=[]
        IO.foreach("#{File.join(basepath,relapath,file)}") do |line| 
          if header && firstline
            headrec = line.split(delim)
            firstline=false
          else
            record = line.split(delim) 
            data << record
          end 
        end # foreach
        #
        return ( header ? [headrec,data] ; data )
        #
      end # def

    end # class self

    begin
      dirNow = Dir.getwd # save current dir
      subpath = 'relative/path/to/data'
      Dir.chdir(ENV['USER']+'/somesubdir')
      records = read_csv_to_array('filename.csv',subpath)
      Dir.chdir(dirNow) # restore the dir
      #
      # do stuff with array of record arrays
      #
    end

  end # module
end # module

If you set header=true, then the returned array will have 2 elements:

the 1st will be the header row array (1 record), * the 2nd will be an multi-record array (an array of record arrays.)
Otherwise with the default (header=false,)
the method would return just an array of record arrays.

EDIT: updated

Reordered arguments to method, all but file with defaults:
relapath (defaults to current dir ['.'])
basepath (defaults to current working dir. [Dir.getwd])
delim (defaults to comma. [','])
header (defaults to false.)

COMMUNITY CONTENT - Public Domain - Author claims no copyright.
Moderators may edit post / correct code snippet(s) at will.

Dan Rathbun

Returning CSV data as an Array of record Hashes

Feel free to change the methodname to suit your taste.


module MyTopLevelNamespace  #<--- you change this
  module MyPlugin           #<--- you change this also
    class<<self

      def read_csv_to_hash_array(file,
                                 relapath='.',
                                 basepath=Dir.getwd,
                                 delim=',',
                                 header=nil)
        firstline=true
        data=[]
        headrec=[]
        IO.foreach("#{File.join(basepath,relapath,file)}") do |line| 
          if header.nil? && firstline
            headrec = line.split(delim)
            firstline=false
          else
            record = line.split(delim) 
            data << record
          end 
        end # foreach
        # use custom hash keys passed in header Array
        headrec = header unless header.nil?
        hasheddata=[]
        data.each do |rec|
          rechash={}
          headrec.each_with_index {|h,i| rechash[h.to_s]=rec[i] }
          hasheddata << rechash.dup
        end # each rec
        #
        return hasheddata
        #
      end # def

    end # class self

    begin
      dirNow = Dir.getwd # save current dir
      subpath = 'relative/path/to/data'
      Dir.chdir(ENV['USER']+'/somesubdir')
      records = read_csv_to_hash_array('filename.csv',subpath)
      Dir.chdir(dirNow) # restore the dir
      #
      # do stuff with array of record hashes
      #
    end

  end # module
end # module

EDIT: updated
header argument
nil (Use firstrow from CSV file as Hash keys.)
['key1','key2',...] (Use Array strings as Hash keys.)

Reordered arguments to method, all but file with defaults:
relapath (defaults to current dir ['.'])
basepath (defaults to current working dir. [Dir.getwd])
delim (defaults to comma. [','])
header (defaults to nil.)

COMMUNITY CONTENT - Public Domain - Author claims no copyright.
Moderators may edit post / correct code snippet(s) at will.

zps222

Hi, Dan, I simply paste "module MyTopLevelNamespace" in to Ruby console window of SU, but the error comes.
Error: #<SyntaxError: (eval):978: compile error
(eval):978: syntax error

So why?

By the way, can I use eclipse to run your code?

Thank you.

Dan Rathbun

[code] reading a CSV file : FAQ

Fequently Asked Questions

What if I have string data that has embeded commas ??

Export your CSV from your spreadsheet using a delimiter other than comma. '||' or '$$' etc.* pass your custom delimiter to the method as the delim argument.

How do I import from a TAB delimited datafile ??

Call the method and specify 9.chr for the delim argument.

COMMUNITY CONTENT - Public Domain - Author claims no copyright.
Moderators may edit post / correct code snippet(s) at will.

Dan Rathbun

@zps222 said:

Hi, Dan, I simply paste "module MyTopLevelNamespace" in to Ruby console window of SU, but the error comes. So why?

A module definition is a block statement. It's meant to be read by the interpreter.

The console is a line evaluation function.
You CAN make a module at the console by putting it all on 1 line, like:
module Zps222; def say_hello(); puts "Hello!"; end; end

YOU are supposed to choose YOUR OWNidentifier for a toplevel module name (namespace.)
Replace "MyTopLevelNamespace" with a unique name that YOU decide. (You can use Zps222, or whatever you want, as long as it is unique for YOU, and noone else will use it.)

Also "MyPlugin", you change it to whatever name you want your plugin to be.

@zps222 said:

By the way, can I use eclipse to run your code?

Yes. This code is not Sketchup specific. It's just plain old standard Ruby.