Key Store

Helper library for filtering and getting object matched to one or more search attribute. Includes a cache so that on repeat calls of the same search criteria the objects do not need re-filtering.

Install

Install with pip via pip install key-store.

Create a new KeyStore

To create a new key-store from a list of object (or dictionaries) and keys

from dataclasses import dataclass

from key_store import KeyStore


@dataclass
class ExampleClass:
    name: str
    value: int
    group: str


# With objects
store = KeyStore(
    keys=["name", "value", "group"],
    objects=[
        ExampleClass(name="Example 1", value=1, group="A"),
        ExampleClass(name="Example 2", value=2, group="B"),
        ExampleClass(name="Example 3", value=3, group="A"),
        ExampleClass(name="Example 4", value=4, group="B"),
    ],
)


# With dictionaries
dict_store = KeyStore(
    keys=["name", "value", "group"],
    objects=[
        {"name": "Example 1", "value": 1, "group": "A"},
        {"name": "Example 2", "value": 2, "group": "B"},
        {"name": "Example 3", "value": 3, "group": "A"},
        {"name": "Example 4", "value": 4, "group": "B"},
    ],
)

From this point onwards the examples will use objects, however all of the same actions can be performed with dictionaries.

If you are using a data class or dictionary then you can use the get_keys function to automatically create you keys input like;

from key_store import get_keys

# Instead of writing out the keys manually you can use
get_keys(ExampleClass) 
# returns: ["name", "value", "group"]

Get One

If you want to search for a single item in your store and get that item the you should use the get one method. For example;

store.get_one(name="Example 1")
# returns: ExampleClass(name="Example 1", value=1, group="A")

Searches can be done using one search criteria as in the example above or multiple like;

store.get_one(group="A", value=3)
# returns: ExampleClass(name="Example 3", value=3, group="A")

If an object matching the search criteria doesn't exist in the store then the get_one function will raise an error;

store.get_one(name="Example 1", group="C")
# returns: a raised error

Get One Or None

If you're not sure if an object matching the search criteria exists in the store and you don't want to raise an error then you can use the get_one_or_none method. For example;

store.get_one_or_none(name="Example 1", group="C")
# returns: None

Get

The get function returns a list of objects that match with the search criteria, or an empty list if none match.

Multiple matches exist;

obj_store.get(group="A")
# returns: [
#    ExampleClass(name="Example 1", value=1, group="A"),
#    ExampleClass(name="Example 3", value=3, group="A"),
#]

A single match exits;

obj_store.get(group="A", value=3)
# returns: [
#    ExampleClass(name="Example 3", value=3, group="A"),
#]

No matches exist;

obj_store.get(name="Not in store")
# returns: []