How to create a new database using SQLAlchemy?

Using SQLAlchemy, an Engine object is created like this:

from sqlalchemy import create_engine
engine = create_engine("postgresql://localhost/mydb")

Accessing engine fails if the database specified in the argument to create_engine (in this case, mydb) does not exist. Is it possible to tell SQLAlchemy to create a new database if the specified database doesn't exist?