keyv

Transform SQLite into a powerful and fast key-value store.

keyv is a lightweight library that turns SQLite into a NoSQL key-value database, combining the best of both worlds: the simplicity of key-value stores with the reliability of SQLite. Perfect for applications that need a robust local database without the complexity of a full DBMS.

Quick Start

For simple use cases, you can create a default collection right away:

pip install keyv

import keyv

# Create a database with a default collection
db = keyv.connect('keyv.db').collection('main')

# Now you can use the collection methods directly
db.set('key1', 'value1')
db.get('key1')
# >>> 'value1'

Usage

import keyv

# initialize the database
db = keyv.connect('keyv.db') # or .anything, since is sqlite3 engine, you can choose any

# create or get a collection
collection = db.collection('my_collection')

# insert a key-value pair
collection.set('key1', 'value1')

# by default the .set method will replace existing values
# if you want to prevent overwriting existing keys, you can
# use replace_if_exists=False
collection.set('key1', 'value1', replace_if_exists=False)

# retrieve a value by key
collection.get('key1')
# >>> 'value1'
# note: the get method returns None for non-existing keys

# update a value
collection.update('key1', 123)
collection.get('key1')
# >>> 123

# delete a key-value pair
collection.delete('key1')

# search for keys by value
collection.set('key2', 'common_value')
collection.set('key3', 'common_value')
collection.search('common_value')
# >>> ['key2', 'key3']

# retrieve all keys, values and items
collection.keys()
# >>> ['key2', 'key3']

# retrieve all values
collection.values()
# >>> ['common_value', 'common_value']

# retrieve all key-value pairs
collection.items()
# >>> [('key2', 'common_value'), ('key3', 'common_value')]

# check if a key exists
collection.key_exists('key2')
# >>> True

# rename a collection
collection.change_name('new_collection_name')

# delete a collection
db.delete_collection('new_collection_name')

# get list of all collections
db.collections()
# >>> ['collection1', 'collection2', ...]

# iterate over key-value pairs
for key, value in collection.iteritems():
    print(f"{key}: {value}")

# iterate over keys
for key in collection.iterkeys():
    print(key)

# iterate over values
for value in collection.itervalues():
    print(value)

# get with default value for missing keys
collection.get('missing_key', default='default_value')
# >>> 'default_value'

# raise exception for missing keys
try:
    collection.get('missing_key', raise_if_missing=True)
except ValueError:
    print("Key not found!")

Collections allow you to organize your data into separate namespaces within the same database file. In practice, they are tables inside the SQLite file.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a PR.