organisciak / yaml-cache

A simple YAML-based cache library for Python

yamlsync

Yaml Sync is a very lightweight YAML-based cache for when you want to preserve the state of something on disk in a human readable way.

Installation

To install Yaml Sync, simply run:

pip install yaml-sync

Example usage

Here's a quick example of how to use Yaml Sync:

from yaml_sync import YamlCache

# Create a cache that reads and writes to the specified file
cache = YamlCache('cache.yaml', mode='rw')

# Save a key to the cache and write to disk
cache['hello'] = 'world'

# Check if a key is in the cache
assert 'hello' in cache

# Retrieve a key from the cache
variable = cache['hello']

# Save a list to the cache
cache['list_example'] = [1, 2, 3]

The resulting yaml will be:

hello: world
list_example:
  0: 1
  1: 2
  2: 3

You can pass number_lists=True at init to save any lists as a numbered dictionary. Since the goal of Yaml Sync is a human-readable file, the numbering may be desired in some cases.

If a value is None, that key is not returned for key in cache. e.g.

cache['empty_key'] = None
assert 'empty_key' in cache
# AssertionError

Finally, you can specify a preferred order to the keys, to control what is shown first in the yaml.

cache = YamlCache('cache.yaml', order=['b', 'a'])

cache['a'] = 'hello'
cache['b'] = 'world'
with open('cache.yaml') as f:
    print(f.read())

b: world
a: hello

License

This project is licensed under the MIT License.