see on GitHub

Session: Storing entities in session

To store entities inside session object use the store method.

def store(self, entity, key=None, etag=None, force_concurrency_check=False):

Syntax

Extracts Id from entity using Conventions or generates new one if it is not available.

session.store(entity)
Extracts Id from entity using Conventions or generates new one if it is not available and forces concurrency check with given etag.
session.store(entity, etag=etag)
Stores entity in session with given id.
session.store(entity, key="doc/1")
Stores entity in session with given id and forces concurrency check with given etag
session.store(entity, key="doc/1", etag=etag)

Parameters
entity object Entity that will be stored
key str Entity will be stored under this key, (None to generate automatically)
etag str Current entity etag, used for concurrency checks (None to skip check)
force_concurrency_check bool Force concurrency check (False as a default value)

Example

# generate Id automatically
# # when we have a new and empty database and conventions are not changed: 'employees/1'
employee = Employee("John", "Doe")
session.store(employee)
session.save_changes()