SAE用flask+MySQL中文'utf8' codec can't decode byte 0xb7解决方法

在Sina App Engine(SAE)上用python flask框架+MySQL搭app服务器时，select返回中文时jsonify函数报如下错误：（为调试放拜我异常时return的traceback.format_exc()）

Traceback (most recent call last): File “/data1/www/htdocs/245/jcguo/1/myapp.py”, line 88, in searchHotel return jsonify(results = data) File “/usr/local/sae/python/lib/python2.7/site-packages/flask/helpers.py”, line 114, in jsonify indent=None if request.is_xhr else 2), mimetype=’application/json’) File “/usr/local/sae/python/lib/python2.7/json/init.py”, line 250, in dumps sort_keys=sort_keys, **kw).encode(obj) File “/usr/local/sae/python/lib/python2.7/json/encoder.py”, line 209, in encode chunks = list(chunks) File “/usr/local/sae/python/lib/python2.7/json/encoder.py”, line 434, in _iterencode for chunk in _iterencode_dict(o, _current_indent_level): File “/usr/local/sae/python/lib/python2.7/json/encoder.py”, line 408, in _iterencode_dict for chunk in chunks: File “/usr/local/sae/python/lib/python2.7/json/encoder.py”, line 332, in _iterencode_list for chunk in chunks: File “/usr/local/sae/python/lib/python2.7/json/encoder.py”, line 390, in _iterencode_dict yield _encoder(value) UnicodeDecodeError: ‘utf8’ codec can’t decode byte 0xb7 in position 4: invalid start byte

大概意思是jsonify时utf8解码器不能解码0xb7，我编码知识比较薄弱，但大概能猜测到是中文的问题。

遂先检查MySQL的database、table以字段的编码设置，确保

SHOW CREATE DATABASE app_jcguo;

返回：

CREATE DATABASE `app_jcguo` /*!40100 DEFAULT CHARACTER SET utf8 */

以及

SHOW CREATE TABLE Hotels

我添加了default charset：

CREATE TABLE `Hotels` (
 `id` int(11) NOT NULL,
 `name` varchar(40) DEFAULT NULL,
 `city` varchar(10) DEFAULT NULL,
 `address` text,
 `price` int(11) DEFAULT NULL,
 `total` int(11) DEFAULT NULL,
 `avail` int(11) DEFAULT NULL,
 `pic_b` varchar(40) DEFAULT NULL,
 `pic_s` varchar(40) DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

属性也都是varchar类型并且设置为utf8_general_ci：

最后Google寻找解决方案，原来是MySQLdb.connect()还要设置一遍charset来指定cursor取数据库数据的格式：

@app.before_request
def before_request():
    g.db = MySQLdb.connect(
        MYSQL_HOST, 
        MYSQL_USER, 
        MYSQL_PASS,
        MYSQL_DB,
        port=int(MYSQL_PORT),
        charset = ‘utf8‘
    )

第一次用MySQL存中文，遇到此坑，遂记录在Blog上。SQLite所有操作默认都是UTF-8，TAT，老用python+SQLite就忽略了这个问题。

对了，文件头中别忘了添加编码注释：

# -*- coding:utf8 -*-
#encoding = utf-8