Firedantic
Database models for Firestore using Pydantic base models.
Installation
The package is available on PyPI:
pip install firedantic
Usage
In your application you will need to configure the firestore db client and optionally
the collection prefix, which by default is empty.
from os import environ
from unittest.mock import Mock
import google.auth.credentials
from firedantic import configure
from google.cloud.firestore import Client
if environ.get("FIRESTORE_EMULATOR_HOST"):
client = Client(
project="firedantic-test",
credentials=Mock(spec=google.auth.credentials.Credentials)
)
else:
client = Client()
configure(client, prefix="firedantic-test-")
Once that is done, you can start defining your Pydantic models, e.g:
from pydantic import BaseModel
from firedantic import Model
class Owner(BaseModel):
"""Dummy owner Pydantic model."""
first_name: str
last_name: str
class Company(Model):
"""Dummy company Firedantic model."""
__collection__ = "companies"
company_id: str
owner: Owner
owner = Owner(first_name="John", last_name="Doe")
company = Company(company_id="1234567-8", owner=owner)
company.save()
print(company.id)
company.reload()
Querying is done via a MongoDB-like find()
:
from firedantic import Model
import firedantic.operators as op
from google.cloud.firestore import Query
class Product(Model):
__collection__ = "products"
product_id: str
stock: int
unit_value: int
Product.find({"product_id": "abc-123"})
Product.find({"stock": {">=": 3}})
Product.find({"stock": {op.GTE: 3}})
Product.find({"stock": {">=": 1}}, order_by=[('unit_value', Query.ASCENDING)], limit=25, offset=50)
Product.find(order_by=[('unit_value', Query.ASCENDING), ('stock', Query.DESCENDING)], limit=2)
The query operators are found at
https://firebase.google.com/docs/firestore/query-data/queries#query_operators.
Async usage
Firedantic can also be used in an async way, like this:
import asyncio
from os import environ
from unittest.mock import Mock
import google.auth.credentials
from google.cloud.firestore import AsyncClient
from firedantic import AsyncModel, configure
if environ.get("FIRESTORE_EMULATOR_HOST"):
client = AsyncClient(
project="firedantic-test",
credentials=Mock(spec=google.auth.credentials.Credentials),
)
else:
client = AsyncClient()
configure(client, prefix="firedantic-test-")
class Person(AsyncModel):
__collection__ = "persons"
name: str
async def main():
alice = Person(name="Alice")
await alice.save()
print(f"Saved Alice as {alice.id}")
bob = Person(name="Bob")
await bob.save()
print(f"Saved Bob as {bob.id}")
found_alice = await Person.find_one({"name": "Alice"})
print(f"Found Alice: {found_alice.id}")
assert alice.id == found_alice.id
found_bob = await Person.get_by_id(bob.id)
assert bob.id == found_bob.id
print(f"Found Bob: {found_bob.id}")
await alice.delete()
print("Deleted Alice")
await bob.delete()
print("Deleted Bob")
if __name__ == "__main__":
asyncio.run(main())
Subcollections
Subcollections in Firestore are basically dynamically named collections.
Firedantic supports them via the SubCollection
and SubModel
classes, by creating
dynamic classes with collection name determined based on the "parent" class it is in
reference to using the model_for()
method.
from typing import Optional, Type
from firedantic import AsyncModel, AsyncSubCollection, AsyncSubModel, ModelNotFoundError
class UserStats(AsyncSubModel):
id: Optional[str] = None
purchases: int = 0
class Collection(AsyncSubCollection):
__collection_tpl__ = "users/{id}/stats"
class User(AsyncModel):
__collection__ = "users"
name: str
async def get_user_purchases(user_id: str, period: str = "2021") -> int:
user = await User.get_by_id(user_id)
stats_model: Type[UserStats] = UserStats.model_for(user)
try:
stats = await stats_model.get_by_id(period)
except ModelNotFoundError:
stats = stats_model()
return stats.purchases
Composite Indexes and TTL Policies
Firedantic has support for defining composite indexes and TTL policies as well as
creating them.
Composite indexes
Composite indexes of a collection are defined in __composite_indexes__
, which is a
list of all indexes to be created.
To define an index, you can use collection_index
or collection_group_index
,
depending on the query scope of the index. Each of these takes in an arbitrary amount of
tuples, where the first element is the field name and the second is the order
(ASCENDING
/DESCENDING
).
The set_up_composite_indexes
and async_set_up_composite_indexes
functions are used
to create indexes.
For more details, see the example further down.
TTL Policies
The field used for the TTL policy should be a datetime field and the name of the field
should be defined in __ttl_field__
. The set_up_ttl_policies
and
async_set_up_ttl_policies
functions are used to set up the policies.
Note: The TTL policies can not be set up in the Firestore emulator.
Examples
Below are examples (both sync and async) to show how to use Firedantic to set up
composite indexes and TTL policies.
The examples use async_set_up_composite_indexes_and_ttl_policies
and
set_up_composite_indexes_and_ttl_policies
functions to set up both composite indexes
and TTL policies. However, you can use separate functions to set up only either one of
them.
Composite Index and TTL Policy Example (sync)
from datetime import datetime
from firedantic import (
collection_index,
collection_group_index,
configure,
get_all_subclasses,
Model,
set_up_composite_indexes_and_ttl_policies,
)
from google.cloud.firestore import Client, Query
from google.cloud.firestore_admin_v1 import FirestoreAdminClient
class ExpiringModel(Model):
__collection__ = "expiringModel"
__ttl_field__ = "expire"
__composite_indexes__ = [
collection_index(("content", Query.ASCENDING), ("expire", Query.DESCENDING)),
collection_group_index(("content", Query.DESCENDING), ("expire", Query.ASCENDING)),
]
expire: datetime
content: str
def main():
configure(Client(), prefix="firedantic-test-")
set_up_composite_indexes_and_ttl_policies(
gcloud_project="my-project",
models=get_all_subclasses(Model),
client=FirestoreAdminClient(),
)
if __name__ == "__main__":
main()
Composite Index and TTL Policy Example (async)
import asyncio
from datetime import datetime
from firedantic import (
AsyncModel,
async_set_up_composite_indexes_and_ttl_policies,
collection_index,
collection_group_index,
configure,
get_all_subclasses,
)
from google.cloud.firestore import AsyncClient, Query
from google.cloud.firestore_admin_v1.services.firestore_admin import (
FirestoreAdminAsyncClient,
)
class ExpiringModel(AsyncModel):
__collection__ = "expiringModel"
__ttl_field__ = "expire"
__composite_indexes__ = [
collection_index(("content", Query.ASCENDING), ("expire", Query.DESCENDING)),
collection_group_index(("content", Query.DESCENDING), ("expire", Query.ASCENDING)),
]
expire: datetime
content: str
async def main():
configure(AsyncClient(), prefix="firedantic-test-")
await async_set_up_composite_indexes_and_ttl_policies(
gcloud_project="my-project",
models=get_all_subclasses(AsyncModel),
client=FirestoreAdminAsyncClient(),
)
if __name__ == "__main__":
asyncio.run(main())
Development
PRs are welcome!
To run tests locally, you should run:
poetry install
poetry run invoke test
Running Firestore emulator
To run the Firestore emulator locally you will need:
To install the firebase
CLI run:
npm install -g firebase-tools
Run the Firestore emulator with a predictable port:
./start_emulator.sh
start_emulator
About sync and async versions of library
Although this library provides both sync and async versions of models, please keep in
mind that you need to explicitly maintain only async version of it. The synchronous
version is generated automatically by invoke task:
poetry run invoke unasync
We decided to go this way in order to:
- make sure both versions have the same API
- reduce human error factor
- avoid working on two code bases at the same time to reduce maintenance effort
Thus, please make sure you don't modify any of files under
firedantic/_sync and
firedantic/tests/tests_sync by hands. unasync
is also
running as part of pre-commit hooks, but in order to run the latest version of tests you
have to run it manually.
Generating changelog
After you have increased the version number in pyproject.toml, please
run the following command to generate a changelog placeholder and fill in the relevant
information about the release in CHANGELOG.md:
poetry run invoke make-changelog
License
This code is released under the BSD 3-Clause license. Details in the
LICENSE file.