aiodatastore

aiodatastore is a low level and high performance asyncio client for Google Datastore REST API. Inspired by gcloud-aio library, thanks!

Key advantages:

• lazy properties loading (that's why it's fast, mostly)

• explicit value types for properties (no types guessing)

• strictly following Google Datastore REST API data structures

Installation

pip install aiodatastore

How to create datastore client

from aiodatastore import Datastore

client = Datastore("project1", service_file="/path/to/file")

You can also set namespace if needed:

from aiodatastore import Datastore

client = Datastore("project1", service_file="/path/to/file", namespace="namespace1")

To use Datastore emulator (for tests or development), just define DATASTORE_EMULATOR_HOST environment variable (usually value is 127.0.0.1:8081).

How to work with keys and entities

from aiodatastore import Key, PartitionId, PathElement

key = Key(PartitionId("project1"), [PathElement("Kind1")])

You can also set namespace for key:

from aiodatastore import Key, PartitionId, PathElement

key = Key(PartitionId("project1", namespace_id="namespace1"), [PathElement("Kind1")])

And id or name for path element:

from aiodatastore import Key, PartitionId, PathElement

key1 = Key(PartitionId("project1"), [PathElement("Kind1", id="12345")])
key2 = Key(PartitionId("project1"), [PathElement("Kind1", name="name1")])

To create an entity object, you have to specify key and properties. Properties is a dict with string keys and typed values. For each data type the library provides corresponding value class. Every value (except ArrayValue) can be indexed or not (indexed by default):

from aiodatastore import Entity, Key, PartitionId, PathElement
from aiodatastore import (
    ArrayValue,
    BoleanValue,
    BlobValue,
    DoubleValue,
    GeoPointValue,
    IntegerValue,
    LatLng,
    NullValue,
    StringValue,
    TimestampValue,
)

key = Key(PartitionId("project1"), [PathElement("Kind1")])
entity = Entity(key, properties={
    "array-prop": ArrayValue([NullValue(), IntegerValue(123), StringValue("str1")]),
    "bool-prop": BooleanValue(True),
    "blob-prop": BlobValue("data to store as blob"),
    "double-prop": DoubleValue(1.23, indexed=False),
    "geo-prop": GeoPointValue(LatLng(1.23, 4.56)),
    "integer-prop": IntegerValue(123),
    "null-prop": NullValue(),
    "string-prop": StringValue("str1"),
    "timestamp-prop": TimestampValue(datetime.datetime.utcnow()),
})

To access property value use .value attribute:

print(entity.properties["integer-prop"].value)
123

Use .value attribute to change property value and keep index status. Or assign new value and set index:

print(entity.properties["integer-prop"].value, entity.properties["integer-prop"].indexed)
123, True
entity.properties["integer-prop"].value = 456
print(entity.properties["integer-prop"].value, entity.properties["integer-prop"].indexed)
456, True

entity.properties["integer-prop"] = IntegerValue(456, indexed=True)
print(entity.properties["integer-prop"].value, entity.properties["integer-prop"].indexed)
456, True

Use .indexed attribute to access or change index:

print(entity.properties["integer-prop"].indexed)
True

entity.properties["integer-prop"].indexed = False
print(entity.properties["integer-prop"].indexed)
False

To insert new entity (the entity key's final path element may be incomplete):

key = Key(PartitionId("project1"), [PathElement("Kind1")])
entity = Entity(key, properties={
    "string-prop": StringValue("some value"),
})
await client.insert(entity)

To update an entity (the entity must already exist. Must have a complete key path):

entity.properties["string-prop"] = StringValue("new value")
await client.update(entity)

To upsert an entity (the entity may or may not already exist. The entity key's final path element may be incomplete):

key = Key(PartitionId("project1"), [PathElement("Kind1")])
entity = Entity(key, properties={
    "string-prop": StringValue("some value"),
})
await client.upsert(entity)

To delete an entity (the entity may or may not already exist. Must have a complete key path and must not be reserved/read-only):

await client.delete(entity)

If you have entity's key or know how to build it:

await client.delete(key)