filter and filter_by in SQLAlchemy

It is a syntax sugar for faster query writing. Its implementation in pseudocode:

def filter_by(self, **kwargs):
    return self.filter(sql.and_(**kwargs))
For AND you can simply write:

Users.query.filter_by(name='Joe', surname='Dodson')
btw

db.users.filter(or_(db.users.name=='Ryan', db.users.country=='England'))
can be written as

db.users.filter((db.users.name=='Ryan') | (db.users.country=='England'))
Also you can get object directly by PK via get method:

Users.query.get(123)
# And even by a composite PK
Users.query.get(123, 321)
When using get case its important that object can be returned without database request from identity map which can be used as cache(associated with transaction)