python 正则使用笔记

def remove_br(content):
    """去除两边换行符"""
    content = content.replace("<br>", "<br />").replace("<br >", "<br />")
    while re.findall("^<br />|<br />$", content):
        content = re.sub(r‘^<br />|<br />$‘, "", content)
    return content


if __name__ == "__main__":
    s =  remove_br("<br><br>ab<br />c<br><br>")
    print s