code: def load_genotypes(self):
          
  
          if DataParser.compressed_pedigree:
              self.genotype_file = gzip.open("%s.gz" % self.tped_file, 'rb')
          else:
              self.genotype_file = open(self.tped_file)
          self.filter_missing()
docs: This really just intializes the file by opening it up.