Python Interface for a Key-Value Database

This is a Python module that provides an interface, the KeyValueDatabaseInterface() class, for a simple Key-Value Database. If such a database does not exists, it creates ones using SQLAlchemy. The interface has several CRUD methods so that it can interface with the database.

Some methods of the KeyValueDatabaseInterface() class return an object of type KeyValue(), which is a class used to abstract the Key-Value entries in the database. This can and probably will change in the future so that the implementation can be hidden. Instead, a dictionary or a tuple will probably be returned instead.

By default the module uses SQLite3 as a database, but it can support any of the ones supported by SQLALchemy.

Connecting to Database

Currently SQLite defaults as the default database. It's a local database saved to a .db file. You can open the database file and view the content using DB Browser for SQLite.

Python Google Protocol Buffer Message() Class Document

Google provides document on the Python Protobuf classes: https://developers.google.com/protocol-buffers/docs/reference/python/. The Message() class is of particular use.

KeyValueDatabaseInterface Methods

KeyValueDatabaseInterface(): An interface class for a simple Key-Value Relational Database. Has several different CRUD methods

get_all(): A method that returns all the Key-Value pairs in the database

• return: list of all Key-Value pairs from the database
• rtype: List

get(key): Returns the entry associated with the key.

• param key: the key of the entry to be retrieved from the database
• type key: string
• return: entry associated with that key
• rtype: KeyValue

get_multiple(keys): Returns a list of entries associated with the provided keys.

• param keys: A list of keys for which to retrieve the entries from the database.
• type keys: List
• return: A list of Key-Value pairs
• rtype: List

insert(self, key, value): Insert a single entry into the database.

• param key: The key for the entry.
• type key: string
• param value: The associated value.
• return: True is the insertion was successful; False otherwise.
• rtype: bool

insert_multiple(kv_values): Insert multiple Key-Value entries.

• param kv_values: A set of Key-Value pairs.
• type kv_values: List<Tuple, List, or Dictionary> or Dictionary<string,value>
• return: True is the insertions were successful; False otherwise.
• rtype: bool

update(key, value): Updates the entry associated with the key with the value provided.

• param key: the entry's key
• param value: the new value of the entry
• return: void

remove(keys): Remove the entries associate with the keys provided.

• param keys: The keys of the entries to remove
• type keys: List
• return: void

Examples

There are two example python files in the project:

• example.py shows how to use the custom Key-Value interface; and
• example_protobuf.py shows how add a serialized protocol buffer.