Returns a random non-zero digit/number
        between 1 and 9 or and empty string.

def random_digit_not_null_or_empty(self):
        """
        Returns a random non-zero digit/number
        between 1 and 9 or and empty string.
        """
        if self.generator.random.randint(0, 1):
            return self.generator.random.randint(1, 9)
        else:
            return ''