how to create mysql database in sqlalchemy?

[junepeach]

I ran below code as a root user:

import sqlalchemy
engine = sqlalchemy.create_engine('mysql://user:password@server') # connect to server
engine.execute("CREATE DATABASE mydb") #create db
engine.execute("USE mydb") # select new db

However the database couldn't be created. The error I got is:
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/strategies.py", line 80, in connect
return dialect.connect(*cargs, **cparams)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 279, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/usr/lib/python2.7/dist-packages/MySQLdb/__init__.py", line 81, in Connect
return Connection(*args, **kwargs)
File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 187, in __init__
super(Connection, self).__init__(*args, **kwargs2)
sqlalchemy.exc.OperationalError: (OperationalError) (1049, "Unknown database 'mydb'") None None

Any idea?

Thank you very much!

LYH