no solution right now other than programmatic construction of the URL object:

from sqlalchemy.engine import URL
url = URL.create("mysql", username="user", password="pw", host="host", database="my@database")
engine = create_engine(url)

we already support @ in the database portion, but it was only tested with a file-only URL.

Mike Bayer has proposed a fix for this issue in the master branch:

URL parsing fixes https://gerrit.sqlalchemy.org/c/sqlalchemy/sqlalchemy/+/2838

Mike Bayer has proposed a fix for this issue in the master branch:

URL parsing fixes https://gerrit.sqlalchemy.org/c/sqlalchemy/sqlalchemy/+/2838

That fix broke our engine connection when we use '@' in our password string, we wanted to avoid using urlib parse quote.
Anyway to revert that fix?

I think the new behaviour is the correct one, since previously it would result in the wrong parsing of the url.
As documented, special characters in the password field should be quoted, so I would suggest quoting the password.

Out of interest, how do I do that in a connection url like this? We configure our app via a config.ini file with

sqlalchemy.url = mysql+pymysql://username:pass@pass@staging.example.org/staging?charset=utf8mb4&ssl_ca=/etc/pki/sntl-ca.crt

Right now the host is parsed as pass@staging.example.org - which of course doesn't work.