# -*- coding: utf-8 -*-
import re
import MySQLdb

pattern = re.compile('@(.*)@.*$')

conn = MySQLdb.connect(
    host='localhost', user='root',
    passwd='password', db='j314', charset='utf8')
cursor = conn.cursor()

cursor.execute(
    """select `id`, `created_by_alias` from w0z9v_content where `catid` = 13 AND `created_by_alias` regexp "^@.*@.*$" limit 400""")

aliases = cursor.fetchall()
for alias in aliases:
    # print alias
    newalias = pattern.match(alias[1])
    # print newalias
    if newalias.group(1) is not None:
        cursor.execute("""
        update w0z9v_content set `created_by_alias`=%s where `id`  = '%s'""", (newalias.group(1), alias[0]))
conn.close