add_to_ner.py

from spacy.pipeline import EntityRuler
from spacy import displacy
import jsonlines

# Create list with entity labels from jsonl file
with jsonlines.open(PROJECT_DIR + "data/skill_patterns.jsonl") as f:
    created_entities = [line['label'].upper() for line in f.iter()]
    
def add_newruler_to_pipeline(skill_pattern_path):
    '''Reads in all created patterns from a JSONL file and adds it to the pipeline after PARSER and before NER'''
    
    new_ruler = EntityRuler(nlp).from_disk(skill_pattern_path)
    nlp.add_pipe(new_ruler, after='parser')
    

def visualize_entity_ruler(entity_list, doc):
    '''Visualize the Skill entities of a doc'''
    
    options = {"ents": entity_list}
    displacy.render(doc, style='ent', options=options)
    
visualize_entity_ruler(created_entities, doc)

in this code
project_dir not defined i want know which file is that can someone explain that ??