A simple ODM (Object Document Mapper) for Deta Base, based on pydantic.
Project description
ODetaM
A simple ODM (Object Document Mapper) for Deta Base base on pydantic.
Installation
pip install odetam
Usage
Create pydantic models as normal, but inherit from DetaModel
instead of
pydantic BaseModel. You will need to set the environment variable
DETA_PROJECT_KEY
to your Deta project key so that databases can be
accessed/created, instead you are working under deta initialized project.
Your also can specify Deta project key in Config class of your model, for
migration from Deta Cloud or importing external Collection (read DetaBase Docs)
This is a secret key, so handle it appropriately (hence the environment variable).
Bases will be automatically created based on model names (changed from
PascalCase/CamelCase case to snake_case). A key
field (Deta's unique id) will
be automatically added to any model. You can supply the key on creation, or
Deta will generate one automatically and it will be added to the object when it
is saved.
Async Support
Async/await is now supported! As of version 1.2.0, you can now
from odetam.async_model import AsyncDetaModel
, inherit from that, and run all
the examples below just the same, but with await
in front of the calls.
You must pip install deta[async]
, to use asynchronous base.
Get All
DetaModel.get_all()
should handle large bases better now, but you should
consider querying instead of getting everything if possible, because it is
unlikely to perform well on large bases.
Example
Basics
import datetime
from typing import List
from odetam import DetaModel
class Captain(DetaModel):
name: str
joined: datetime.date
ships: List[str]
# create
kirk = Captain(
name="James T. Kirk",
joined=datetime.date(2252, 1, 1),
ships=["Enterprise"],
)
sisko = Captain(
name="Benjamin Sisko",
joined=datetime.date(2350, 1, 1),
ships=["Deep Space 9", "Defiant"],
)
# initial save, key is now set
kirk.save()
# update the object
kirk.ships.append("Enterprise-A")
# save again, this will be an update
kirk.save()
sisko.save()
Captain.get_all()
# [
# Captain(
# name="James T. Kirk",
# joined=datetime.date(2252, 01, 01),
# ships=["Enterprise", "Enterprise-A"],
# key="key1",
# ),
# Captain(
# name="Benjamin Sisko",
# joined=datetime.date(2350, 01, 01),
# ships=["Deep Space 9", "Defiant"],
# key="key2",
# ),
# ]
Captain.get("key1")
# Captain(
# name="James T. Kirk",
# joined=datetime.date(2252, 01, 01),
# ships=["Enterprise", "Enterprise-A"],
# key="key1",
# )
Captain.get("key3")
# Traceback (most recent call last):
# File "<stdin>", line 1, in <module>
# odetam.exceptions.ItemNotFound
Captain.get_or_none("key3")
# None
Captain.query(Captain.name == "James T. Kirk")
# Captain(
# name="James T. Kirk",
# joined=datetime.date(2252, 01, 01),
# ships=["Enterprise", "Enterprise-A"],
# key="key1",
# )
Captain.query(Captain.ships.contains("Defiant"))
# Captain(
# name="Benjamin Sisko",
# joined=datetime.date(2350, 01, 01),
# ships=["Deep Space 9", "Defiant"],
# )
Captain.query(Captain.name.prefix("Ben"))
# Captain(
# name="Benjamin Sisko",
# joined=datetime.date(2350, 01, 01),
# ships=["Deep Space 9", "Defiant"],
# )
kirk.delete()
Captain.delete_key("key2")
Captain.get_all()
# []
# you can also save several at once for better speed
Captain.put_many([kirk, sisko])
# [
# Captain(
# name="James T. Kirk",
# joined=datetime.date(2252, 01, 01),
# ships=["Enterprise", "Enterprise-A"],
# key="key1",
# ),
# Captain(
# name="Benjamin Sisko",
# joined=datetime.date(2350, 01, 01),
# ships=["Deep Space 9", "Defiant"],
# key="key2",
# ),
# ]
Async model
import datetime
from typing import List
from odetam.async_model import AsyncDetaModel
class Captain(AsyncDetaModel):
name: str
joined: datetime.date
ships: List[str]
async foo():
items = await Captain.get_all()
Config
class Captain(AsyncDetaModel):
name: str
joined: datetime.date
ships: List[str]
class Config:
table_name = "my_custom_table_name"
deta_key = "123_123" # project key from Deta Cloud or Data Key from another Deta Space project
Save
Models have the .save()
method which will always behave as an upsert,
updating a record if it has a key, otherwise creating it and setting a key.
Deta has pure insert behavior, but it's less performant. If you need it, please
open a pull request.
Querying
All basic comparison operators are implemented to map to their equivalents as
(Model.field >= comparison_value)
. There is also a .contains()
and
.not_contains()
method for strings and lists of strings, as well as a
.prefix()
method for strings. There is also a .range()
for number types
that takes a lower and upper bound. You can also use &
as AND and |
as OR.
ORs cannot be nested within ands, use a list of options as comparison instead.
You can use as many ORs as you want, as long as they execute after the ANDs in
the order of operations. This is due to how the Deta Base api works.
Deta Base
Direct access to the base is available in the dunder attribute __db__
, though
the point is to avoid that.
Exceptions
DetaError
: Base exception when anything goes wrong.ItemNotFound
: Fairly self-explanatory...InvalidDetaQuery
: Something is wrong with queries. Make sure you aren't using queries with unsupported types
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