best way to run python generator cleanup code

Question

I\'m trying to write a generator function that gets rows out of a database and returns them one at a time. However, I\'m not sure if the cleanup code marked ** below execute

Answer 1

You can use a context manager and the with statement. contextlib provides closing:

from contextlib import closing

myDB = MySQLdb.connect(host=..., port=..., user=..., passwd=..., db=...)   
with closing(myDB.cursor()) as dbc:
    dbc.execute(stmt)
    d = "asdf"
    while d is not None:
        d = dbc.fetchone() #can also use fetchmany() to be more efficient
        yield d

This will automatically call close() on dbc at the end of the with block, even if an exception has been raised.