text: import os
  
  from PolTools.utils.make_random_filename import generate_random_filename
  from PolTools.utils.verify_bed_file import verify_bed_files
  from PolTools.utils.constants import hg38_fasta_file
  
  
  def run_getfasta(regions_file, output_filename=''):
      """
      Runs strand specific bedtools getfasta to get the sequence at the regions in the regions_file.
  
      :param regions_filename: filename of the regions of the genome to quantify
      :type regions_filename: str
      :param output_filename: optional name of the output file (will be random if not provided)
      :type output_filename: str
      :return: filename of the resultant bedtools fasta output
      :rtype: str
      """
  
      if output_filename == '':
          output_filename = generate_random_filename(extension=".fa")
  
      verify_bed_files(regions_file)
  
      os.system("bedtools getfasta -s -fi " + hg38_fasta_file + " -bed " + regions_file + " > " + output_filename)
  
      return output_filename
  