PesdaDB

A Key-Value database for the command-line and in Python, backed by SQLite3

Overview

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py 
ERROR: No command specified
usage: settings.py [-h]
                   [--get KEY DEFAULT | --set KEY VALUE | --set-default KEY VALUE | --del KEY | --create]
                   [--db DATABASE]
Get/Set Key-Values in a database
optional arguments:
  -h, --help            show this help message and exit
  --get KEY DEFAULT     GET a value with key KEY and value DEFAULT if not set
  --set KEY VALUE       SET a value with key KEY and value VALUE
  --set-default KEY VALUE
                        SET a value ONLY IF KEY does NOT already exist (used
                        for populating defaults)
  --del KEY             DELETE a key and value with key KEY
  --create              Create schema
  --db DATABASE         Specify Database path (you can also set an environment
                        variable 'PESDADB' which will be overriden by --db)

Specify path to database

(you can also use --db <path> on every call if you like)

you@computer:~ $ export PESDADB=/tmp/my_pesdadb_store.db

Manually create it first

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --create

Set and Get a string

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --set foo bar
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get foo ""
bar

It always wants a default value

…in case the key does not exist, but just specify an empty string if you don’t care, (as above)

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get foo2 bar2
bar2

Set a default value

If you want to overwrite a set of new default settings for your program, then this won’t replace any existing ones

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --set-default foo fuzz
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get foo ""
bar

Send in JSON, get back JSON

In fact it will only store valid json. Then you can chain it to JQ or something, if you like

you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --set my_array '["zuli", "kyan", "lars", "fozz"]'
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get my_array "[]"
["zuli", "kyan", "lars", "fozz"]
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get my_array "[]" | jq '.'
[
  "zuli",
  "kyan",
  "lars",
  "fozz"
]
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get my_array "[]" | jq '.[2]'
"lars"
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --set my_object '{"goodies": ["elsa", "anna", "kristoff", "sven", "olaf"], "baddies": ["marshmallow", "hans", "weaselman"]}'
you@computer:~ $ python3 ~/PesdaDB/pesdadb.py --get my_object "{}" | jq '.baddies[0]'
"marshmallow"

Why

I needed a robust key/value store that can be:

• Used simulataneously between many programs at the same time.
• Used in Python and on the CLI
• Handle JSON & with safe defaults

It’s built upon the ubiquitous and amazing Sqlite3 which does all of the hard work to satisfy my wishlist above, and so PesdaDB is just a Python wrapper for some SQL commands.

License

PesdaDB is provided under the MIT license,
but if you use it commercially or otherwise, please consider sending a postcard, by mail from wherever you live, to:

Rob & Family
EvoMetric
G58
Menai Science Park
Gaerwen
Anglesey
LL60 6AG
UNITEC KINGDOM