python的with语句怎样嵌套使用？

number321

from contextlib import closing
import MySQLdb
try:
    conn = MySQLdb.connect("localhost", "root", "root", "abc")
    with closing(conn.cursor()) as cur:
        cur.execute("insert into abc values(default,'Jack','Male',26)")
        cur.execute("select * from abc")
        for row in cur.fetchmany(2):
            for column in row:
                print column,
            print ''
except MySQLdb.Error,e:
     print "Mysql Error %d: %s" % (e.args[0], e.args[1])
finally:
    conn.close()

上面这样没有问题，但是下面这样就会报错：
from contextlib import closing
import MySQLdb
with MySQLdb.connect("localhost", "root", "root", "abc") as conn:
    with closing(conn.cursor()) as cur:
        cur.execute("insert into abc values(default,'Jack','Male',26)")
        cur.execute("select * from abc")
        for row in cur.fetchmany(2):
            for column in row:
                print column,
            print ''

报错是
File "D:/PyProject/HelloWorld/HelloWorld.py", line 4, in <module>
    with closing(conn.cursor()) as cur:
AttributeError: 'Cursor' object has no attribute 'cursor'

不可以像这样使用吗？

number321

我知道原因了。。
with MySQLdb.connect("localhost", "root", "root", "abc") as conn:
也要改成这样：
with closing(MySQLdb.connect("localhost", "root", "root", "abc")) as conn: