Fix pager spaces

def fill_pager(self, page):
        """Fix pager spaces
        """
        tty_size = os.popen("stty size", "r").read().split()
        rows = int(tty_size[0]) - 1
        lines = sum(1 for line in page.splitlines())
        diff = rows - lines
        fill = "\n" * diff
        if diff > 0:
            return fill
        else:
            return ""