make_purged_copy.rb

def lawyer?(line_to_check)
  #some code to check if line is a lawyer
end

def doctor?(line_to_check)
 #some code to check if line is a doctor
end


def create_purged_copy(#somehow pass one of the above (or I suppose any) functions as an argument here...call it some_condition()#,working_path )

  File.open(working_path+"/datasample.csv","r") do |source_file|
    File.open(working_path+"/dest.csv","w") do |dest_file|
      source_file.each_line do |line|
        if some_condition(line)
          dest_file << line
        end
      end
    end
  end


end