This really just intializes the file by opening it up.

def load_genotypes(self):
        """This really just intializes the file by opening it up. """

        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()