I think this is a bug in MySQLdb .

text_mysqldb.py

import MySQLdb

conn = MySQLdb.connect(user='xxx',passwd='xxx',db = 'xxx')

cursor = conn.cursor()

n = cursor.execute(
    'select * from xxx where `content` in %(content)s',
    { 'content': ('aa','bb','cc') }
)
print cursor._last_executed

# I hope it print:
# select * from xxx where `content` in ('aa', 'bb', 'cc')
# but actually it print:
# select * from xxx where `content` in ("'aa'", "'bb'", "'cc'")
# and because of this , the query fetch nothing
# Is this a bug of MySQLdb ?

# my system:
# Ubuntu 12.04.2 LTS
# Python 2.7.3
# MySQLdb 1.2.3