Entityshape

A python library to compare a wikidata item with an entityschema

Based on https://github.com/Teester/entityshape by Mark Tully and https://github.com/dpriskorn/PyEntityshape by Dennis Priskorn

Features

• compare a given wikidata item with an entityschema and dig into missing properties, too many statement, etc.
• determine whether an item is valid according to a certain schema or not

Limitations

The shape and compareshape classes currently only support:

• cardinality (too many or not enough values)
• whether the property is allowed or not
• whether the value of a statement on a given property is correct/incorrect

It is still a bit unclear if and how the qualifier validation works.

Only Wikidata is supported currently when fetching labels for the result. If you need support for other Wikibase installations, comment here.

Installation

Get it from pypi

$ pip install pyentityshape

Usage

Jupyter Notebooks

Example notebooks with code for validation of multiple items: hiking paths campsites shelters

CLI

Example:

e = EntityShape(eid="E1", lang="en", qid="Q1")
result = e.validate_and_get_result()
# Get human readable result
print(result)
"Valid: False\nProperties_without_enough_correct_statements: instance of (P31)"
# Access the data
print(result.properties_without_enough_correct_statements)
"{'P31'}"

Validation

The is_valid method on the Result object mimics all red warnings displayed by https://www.wikidata.org/wiki/User:Teester/EntityShape.js

It currently checks these five conditions that all have to be false for the item to be valid:

1. properties with too many statements found
2. incorrect statements found
3. some required properties are missing
4. properties without enough correct statements found
5. statements with properties that are not allowed found

Known working schemas

This library currently only supports a subset of all features in the ShEx specification.

The following Entity Schemas are known to work:

• hiking path
• shelter

Background

This library is the glue between libraries like Wikibase Integrator and entityschemas.

It makes it easy to batch check a whole subset of Wikidata items against a schema. Nice!

TODO

The CompareShape and Shape classes should be rewritten using OOP and enums to avoid passing strings around because that is not nice to debug or maintain.

What do we want to know from the CompareShape class?

On the property level:

• whether the property is mandatory and present/missing

On the statement level

• whether the cardinality of values is allowed (min/max)
• whether the value(s) are correct/incorrect

Cases:

• mandatory property is missing
• optional property is missing (this is not invalidating)
• a property has an incorrect value
• a property has a correct value
• a property has too many values
• a property has not enough values
• ?

ShEx Tip

When working on your Entity Schemas the constraints here are nice to know/remember https://shex.io/shex-primer/#tripleConstraints

Thanks

Big thanks to Myst and Christian Clauss for advice and help with Ruff to make this better.

License

GPLv3+

What I learned

• Forking other peoples undocumented spaghetti code is not much fun.
• I want to find a more reliable validator that support somevalue and novalue
• Pydantic is wonderful yet again it makes working with OOP easy peasy :)
• Ruff is crazy fast and very nice!