已经装了MySQL-python，但在引用时报错：ImportError: No?报错

已经用yum安装了MySQL-python：

$ yum list MySQL-python
Installed Packages
MySQL-python.x86_64        1.2.3-0.3.c1.1.el6              @base

但在python中引入MySQLdb时报错：

$ python
Python 2.7.6 (default, Nov 19 2014, 11:10:02) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-11)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named MySQLdb

查询到在系统中是有下面这个目录的：

/usr/lib64/python2.6/site-packages/MySQLdb

希望高手帮忙看看。