Why Connection.__exit__ doesn't use Cursor.close

[adcro...@gmail.com]

Hy,

I'm using
with self.connection as cur:

and was expecting Cursor.close to be called automatically at the end, but isn't. Why is that?

Thanks!

[INADA Naoki]

Since it's not defined in DB-API 2.0 <https://www.python.org/dev/peps/pep-0249>

I've added __enter__ and __exit__ to MySQLdb (and mysqlclient), but it
is for transaction.
https://github.com/PyMySQL/mysqlclient-python/blob/master/MySQLdb/connections.py

Now, I'm afraid to add it without DB-API recommendation.

> --
> You received this message because you are subscribed to the Google Groups
> "PyMySQL Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to pymysql-user...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.



--
INADA Naoki <songof...@gmail.com>

[adcro...@gmail.com]

So, I'm new to PyMysql, so I'm a little confused.

I'm talking about this code:

def __enter__(self):

if self.get_autocommit():

self.query("BEGIN")

return self.cursor()

def __exit__(self, exc, value, tb):

if exc:

self.rollback()

else:

self.commit()

On __enter__ self.cursor() is called and a new Cursor is created. Shouldn't it be closed on __exit__?

[Naoki INADA]

Uh, You're right.

Since PyMySQL's cursor doesn't grasp any resource, not closing it doesn't cause leak.

[adcro...@gmail.com]

So, why does a close() method exist at all, if its not used/useful?
And why is it "public"?

[INADA Naoki]

It's necessary since it's defined in DB-API 2.0.

[adcro...@gmail.com]

Thanks for your time!
It's really helpful to learn from a good source :)