sqlitent

sqlitent - namedtuples inside sqlite databases

sqlitent provides a set-like interface on top of SQLite_. Values can be None, int, float, str, and bytes. Tuple types are distinguished by name (case sensitive!) and number of fields. Documentation_.

sqlitent was inspired by sqlitedict_ and kv_.

Example

::

>>> from collections import namedtuple
>>> from sqlitent import sqlitent, fuzzy
>>> db = sqlitent('database.sqlite', autocommit=True)
>>>
>>> Point = namedtuple('Point', ['x', 'y'])
>>> p1 = Point(11, y=22)
>>> p1
Point(x=11, y=22)
>>> p2 = p._replace(x=33)
Point(x=33, y=22)
>>> Car = namedtuple('Car', [
...     'brand',
...     'model',
...     'configuration',
...     'hp',
... ])
>>> c = Car('Audi', 'A1', 'Sport 1.8 TFSI S tronic', 192)
>>> c
Car(brand='Audi', model='A1', configuration='Sport 1.8 TFSI S tronic', hp=192)
>>> db.register(Point, Car)  # necessary to read tuples

In addition to the methods which the set type provides, there are convenience methods (insert, delete) that handle multiple tuples at once.

::

>>> db.add(p1)
>>> db.remove(p1)
>>> db.insert(p1, p2)
>>> db.delete(p1, p2)
>>> db.insert([p1], [[p1], p2])
>>> db.insert(c)
>>> db.insert([c, p1])  # tuples may be of different types

Of course, sqlitent also supports membership checking and counting:

::

>>> d = c._replace(configuration='1.6 TDI S tronic', hp=116)
>>> d in db
False
>>> len(db)
3
>>> db.insert(d)
>>> d in db
True
>>> len(db)  # ...now we have 4 unique tuples in the database.
4

There are various ways to retreive tuples from the database:

::

>>> p3 = db.one(Point)  # not deterministic
>>> p3
Point(x=11, y=22)
>>> p3 = db.one(p3)  # deterministic (since p3 is fully specified)
>>> p3 in db
True
>>> db.pop(p3)  # remove and return
Point(x=11, y=22)
>>> p3 in db
False
>>> db.pop(Point)  # not deterministic
Point(x=33, y=22)
>>> db.pop(Point)  # returns None since there are no more Point tuples
>>>

Obviously there are also functions to retrieve or pop multiple values out of the database. sqlitent also supports fuzzy matching on text fields and filter functions:

::

>>> cs = db.many(Car)  # get all cars
>>> cs
<generator object _sqlitent_iter at 0x10f39bb48>
>>> list(cs)
[Car(brand='Audi', model='A1', configuration='Sport 1.8 TFSI S tronic', hp=192),
 Car(brand='Audi', model='A1', configuration='1.6 TDI S tronic', hp=116)]
>>> d = list(db.popmany(Car, configuration=fuzzy('%TDI%')))
>>> any(x in db for x in d)  # we removed all TDI cars from the database
False
>>> list(db.many(Car, hp=lambda v: v > 150))
[Car(brand='Audi', model='A1', configuration='Sport 1.8 TFSI S tronic', hp=192)]
>>> list(db.many(Car, brand='Kia'))
[]

This library is MIT licensed.

.. _Sqlite: https://sqlite.org/ .. _Documentation: https://digitalmensch.github.io/sqlitent/ .. _sqlitedict: https://github.com/RaRe-Technologies/sqlitedict .. _kv: https://github.com/mgax/kv .. _code: https://github.com/digitalmensch/sqlitent