PyLoDStorage

OsProject

OsProject
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id	PyLodStorage
state
owner	Wolfgang Fahl
title	python List of Dict (Table) Storage library
url	https://github.com/WolfgangFahl/pyLodStorage
version	0.0.12
description
date	2020/09/21
since
until

see also DgraphAndWeaviateTest

List of Dicts = Table

a list of dicts(Hashtables) in python can be interpreted as Table which is suitable to be stored

1. in a relational database like sqlite3
2. as JSON

Royals example

 @staticmethod
    def getRoyals():
        listOfDicts=[
            {'name': 'Elizabeth Alexandra Mary Windsor', 'born': Sample.dob('1926-04-21'), 'numberInLine': 0, 'wikidataurl': 'https://www.wikidata.org/wiki/Q9682' },
            {'name': 'Charles, Prince of Wales',         'born': Sample.dob('1948-11-14'), 'numberInLine': 1, 'wikidataurl': 'https://www.wikidata.org/wiki/Q43274' },
            {'name': 'George of Cambridge',              'born': Sample.dob('2013-07-22'), 'numberInLine': 3, 'wikidataurl': 'https://www.wikidata.org/wiki/Q1359041'},
            {'name': 'Harry Duke of Sussex',             'born': Sample.dob('1984-09-15'), 'numberInLine': 6, 'wikidataurl': 'https://www.wikidata.org/wiki/Q152316'}
        ]
        today=date.today()
        for person in listOfDicts:
            born=person['born']
            age=(today - born).days / 365.2425
            person['age']=age
            person['ofAge']=age>=18
            person['lastmodified']=datetime.now()
        return listOfDicts

The above list of dict can be stored in a Person table with the following structure:

SQL

The idea is to derive the necessary DDL and SQL command automatically:

CREATE TABLE Family(name TEXT PRIMARY KEY,country TEXT,lastmodified TIMESTAMP)
INSERT INTO Family (name,country,lastmodified) values (:name,:country,:lastmodified)

and use them via simple API

from lodstorage.sample import Sample
from lodstorage.sql import SQLDB, EntityInfo

 listOfRecords=Sample.getRoyals()
 sqlDB=SQLDB()
 entityName='Person'
 primaryKey='name'
 entityInfo=self.sqlDB.createTable(listOfRecords[:10],entityName,primaryKey)
 sqlDB.store(listOfRecords,entityInfo)
 resultList=self.sqlDB.queryAll(entityInfo)

The resultList will be the same as the original listOfRecords.

Apache Jena

The jena -l and jena -f options will automatically download and unpack the needed Apache jena files.

Jena load example dataset

scripts/jena -l sampledata/example.ttl

Jena fuseki server start

scripts/jena -f example

You should be able to browse the admin GUI at http://localhost:3030 and have the example dataset ready for you

Jena fuseki server stop

scripts/jena -k

jena script usage

scripts/jena -h
scripts/jena [-f|--fuseki|-h|--help|-k|--kill|-l|--load]

-f | --fuseki [dataset]: download and start fuseki server with the given dataset
-h | --help: show this usage
-k | --kill: kill the running fuseki server
-l | --load [ttl file]: download jena / tdbloader and load given ttl file