sqlalchemy The Session Creating a Session
Example
A session is usually obtained using sessionmaker, which creates a Session class unique to your application. Most commonly, the Session class is bound to an engine, allowing instances to use the engine implicitly.
from sqlalchemy.orm import sessionmaker
# Initial configuration arguments
Session = sessionmaker(bind=engine)
The engine and Session should only be created once.
A session is an instance of the class we created:
# This session is bound to provided engine
session = Session()
Session.configure() can be used to configure the class later, e.g. application startup rather than import time.
Session = sessionmaker()
# later
Session.configure(bind=engine)
Arguments passed to Session directly override the arguments passed to sessionmaker.
session_bound_to_engine2 = Session(bind=engine2)
