text: #!/usr/bin/python3
  
  import os
  import qlibs 
  
  #
  # Filename: selectby.py
  # Author: Saverio Simonelli <saverio.simonelli.95@gmail.com>
  # Copyright: 2020 Saverio Simonelli 
  # License: MIT license
  #
  
  def select_by(population, infile, outfile, nval, val):
      print(infile)
      rows = qlibs.get_rows(infile)
      header = 1000
      text = ""
      posgs = -1
      for i in range(len(rows)):
          cols = rows[i].split(";")
          if len(cols) > 1:
              if header == 1000:
                  text = rows[i] + ("\n")
                  header = i
                  hcols = rows[i].split(";")
                  posgs = qlibs.find(nval, hcols)
                  if posgs == -1:
                      posgs = qlibs.find(nval.replace('"',''), hcols)
                      if posgs == -1:
                          qlibs.trace("selectBy", infile, population)
                          return
              if i > header:
                  if cols[posgs] == val: text = text + rows[i] + "\n"
      fout = open(outfile, "w")
      fout.write(text)
      fout.close()
      return 
  