Prefixing

Prefixing is a very simple but powerful feature of KV. It allows you to namespace keys and search by prefix.

Example

Let's say we're storing documents per user. We can prefix each's documents by their ID, so that:

• No conflicts occur between users
• We can quickly query all documents for a user

Namespacing

from kv import KV

kv = KV.of('file://users', type=dict)
kv1 = kv.prefix('user1')
kv2 = kv.prefix('user2')

await kv1.insert('settings', {'theme': 'dark'})
await kv2.insert('settings', {'theme': 'light'})

This will yield:

users/
  user1/
    settings.json
  user2/
    settings.json

Prefix Querying

Say we want to get all documents for user1:

user1_keys = [key async for key in kv.prefix('user1').keys()] # ['settings']

Nested Prefixing

You can imagine a complexer scenario with nested namespacing. No problem at all!

kv.prefix('user1/images/cats')

Backend Support

Prefixing has a default implementation using string prefixes. Specific backends may provide more efficient implementations (like the filesystem).

To check out the details, check out the specific backend pages. Links can be found in the Supported Backends page.