python转换字符集

def URLtoUTF8(string):
    """"""
    g_code_type = ['utf-8', 'utf8', 'gb18030', 'gb2312', 'gbk', 'ISO-8859-2']
    try:
        tmp = urllib.unquote(str(string))
        code = chardet.detect(tmp)['encoding']
        try:
            g_code_type.index(code.lower())
            tmp = tmp.decode(code)
        except:
            try:
                tmp = tmp.decode('utf8')
            except:
                tmp = tmp.decode('gb18030')
    except:
        tmp = json.dumps(string)
        tmp = tmp.replace(u'"','')
        pass
    tmp = tmp.replace(u'\xa0',' ')
    return tmp