how to set autocommit = 1 in a sqlalchemy.engine.Connection

What is your dialect for mysql connection?

You can set the autocommit to True to solve the problem, like this mysql+mysqldb://user:password@host:port/db?charset=foo&autocommit=true

From The SQLAlchemy documentation: Understanding autocommit

conn = engine.connect()
conn.execute("INSERT INTO users VALUES (1, 'john')")  # autocommits

The “autocommit” feature is only in effect when no Transaction has otherwise been declared. This means the feature is not generally used with the ORM, as the Session object by default always maintains an ongoing Transaction.

Full control of the “autocommit” behavior is available using the generative Connection.execution_options() method provided on Connection, Engine, Executable, using the “autocommit” flag which will turn on or off the autocommit for the selected scope. For example, a text() construct representing a stored procedure that commits might use it so that a SELECT statement will issue a COMMIT:

engine.execute(text("SELECT my_mutating_procedure()").execution_options(autocommit=True))

You can use this:

from sqlalchemy.sql import text

engine = create_engine(host, user, password, dbname)
engine.execute(text(sql).execution_options(autocommit=True))