Bloop is an object mapper for DynamoDB and DynamoDBStreams.

Requires Python 3.6+

pip install bloop

Usage

First, we need to import all the things:

>>>frombloopimport (
... BaseModel, Boolean, Column, String, UUID,
... GlobalSecondaryIndex, Engine
... )

Next we'll define the account model (with streaming enabled), and create the backing table:

>>>classAccount(BaseModel):
... classMeta:
... stream= {
... "include": {"old", "new"}
... }
... id=Column(UUID, hash_key=True)
... name=Column(String)
... email=Column(String)
... by_email=GlobalSecondaryIndex(projection='keys', hash_key='email')
... verified=Column(Boolean, default=False)
...
>>>engine=Engine()
>>>engine.bind(Account)

Let's make a few users and persist them:

>>>importuuid>>>admin=Account(id=uuid.uuid4(), email="admin@domain.com")
>>>admin.name="Admin McAdminFace">>>support=Account(name="this-is-fine.jpg", email="help@domain.com")
>>>support.id=uuid.uuid4()
>>>engine.save(admin, support)

Or do the same in a transaction:

>>>withengine.transaction() astx:
... tx.save(admin)
... tx.save(support)
...
>>>

And find them again:

>>>q=engine.query(
... Account.by_email,
... key=Account.email=="help@domain.com"
... )
>>>q.first()
Account(email='help@domain.com',
id=UUID('d30e343f-f067-4fe5-bc5e-0b00cdeaf2ba'),
verified=False)

>>>s=engine.scan(
... Account,
... filter=Account.name.begins_with("Admin")
... )
>>>s.one()
Account(email='admin@domain.com',
id=UUID('08da44ac-5ff6-4f70-8a3f-b75cadb4dd79'),
name='Admin McAdminFace',
verified=False)

Let's find them in the stream:

>>>stream=engine.stream(Account, "trim_horizon")
>>>next(stream)
{'key': None,
'meta': {'created_at': datetime.datetime(...),
'event': {'id': 'cbb9a9b45eb0a98889b7da85913a5c65',
'type': 'insert',
'version': '1.1'},
'sequence_number': '100000000000588052489'},
'new': Account(
email='help@domain.com',
id=UUID('d30e343f-...-0b00cdeaf2ba'),
name='this-is-fine.jpg',
verified=False),
'old': None}
>>>next(stream)
{'key': None,
'meta': {'created_at': datetime.datetime(...),
'event': {'id': 'cbdfac5671ea38b99017c4b43a8808ce',
'type': 'insert',
'version': '1.1'},
'sequence_number': '200000000000588052506'},
'new': Account(
email='admin@domain.com',
id=UUID('08da44ac-...-b75cadb4dd79'),
name='Admin McAdminFace',
verified=False),
'old': None}
>>>next(stream)
>>>next(stream)
>>>

What's Next

Check out the User Guide or Public API Reference to create your own nested types, overlapping models, set up cross-region replication in less than 20 lines, and more!