helper/src/myontology.py

from typing import List, Optional

from owlready2 import get_ontology, Ontology


class MyOntology:
    def __init__(self) -> None:
        self.__onto: Ontology = get_ontology("file://./ontology.owl").load()

    def __find_str_in_list(self, string: str, string_list: List[str]) -> int:
        try:
            string_list.index(string)
            return 1
        except ValueError:
            return 0

    def __get_property_value(self, values: [], instance):
        if len(values) != 1:
            raise ValueError(f'Wrong values in {instance.name}')
        return values[0]

    def __get_event_instance(self, instances: []):
        max_instance: Optional = None
        max_priority: int = 0
        for instance in instances:
            event = self.__get_property_value(instance.hasEvent, instance)
            priority = self.__get_property_value(event.hasPriority, event)
            if priority > max_priority:
                max_instance = event
                max_priority = priority
        return max_instance

    def __find_instances_by_terms(self, nouns: List[str]) -> []:
        instances = []
        for instance in self.__onto.Concept.instances():
            terms = instance.hasTerm
            match: int = 0
            for term in terms:
                match = match + self.__find_str_in_list(term.name, nouns)
            if match >= len(terms) * 0.5:
                instances.append(instance)
        return instances

    def get_event_description(self, nouns: List[str]) -> str:
        instances: [] = self.__find_instances_by_terms(nouns)
        event = self.__get_event_instance(instances)
        if event is None:
            return ''
        return self.__get_property_value(event.hasDescription, event)