Google once implemented their own mapping guidance google/freebase-wikidata-converter. However, it hasn't been updated for 8 years (it's 2023 at the time of writing). And the respository has been archived in 2022. This repository provides the best-effort mapping.
Since the mapping relies on real-time query, the results can always be up-to-date. The notebook conversion.ipynb provides detailed guidance on the mapping.
We map the enities by looking up the Freebase ID attribute of Wikidata entities,following the advice from Freebase FAQ:
How can I map my Freebase Mids to Wikidata Qids?
Wikidata has the property Freebase ID (P646) to add the Mid on a Wikidata item. Using WDQ, you can map single Mids to their Wikidata Item Qids, e.g. Query: string[646:"/m/02mjmr"]. You can also download Wikidata data and access Freebase ID (P646) in any of the other ways described here, i.e. from the dump, through the entity API, etc. See Wikidata:Data access for more details.
Usage:
from converter import EntityConverter
entity_converter = EntityConverter("https://query.wikidata.org/sparql")
entity_converter.get_wikidata_id("/m/0dgw9r") # 'Q15978631'
entity_converter.get_freebase_id("Q42") # '/m/0282x'
entity_converter.get_wikidata_id("/m/0dgw9r", limit=3) # ['Q15978631', 'Q5']4818298 entities from Wikidata5m are mapped and saved as a dictionary at fid2qid.pkl.
The same FAQ page suggests to use equivalent property attribute to convert the properties. But it turns out that the Freebase link does not present in any property.
We get the latest property mapping by scraping WikiProject Freebase/Mapping , which stores all existing property mappings.
Usage:
from converter import PropertyConverter
property_converter = PropertyConverter("https://www.wikidata.org/wiki/Wikidata:WikiProject_Freebase/Mapping")
property_converter.get_wikidata_property("/organization/organization/child") # 'P355'
property_converter.get_freebase_property("P355") # '/organization/organization/child'