utils.py

import pandas as pd
from datetime import datetime
import requests
import json


def convert_datatype(entry):
    if 'datatype' in entry:
        if entry['datatype'] == 'http://www.w3.org/2001/XMLSchema#decimal':
            return float(entry['value'])
        elif entry['datatype'] == 'http://www.w3.org/2001/XMLSchema#integer':    
            return int(entry['value'])
        elif entry['datatype'] == 'http://www.w3.org/2001/XMLSchema#dateTime':
            date = entry['value']
            date = None if date.startswith('t') else datetime.strptime(date, '%Y-%m-%dT%H:%M:%SZ')
            return date
    return entry['value']


def wikidata_query(query):
    url = 'https://query.wikidata.org/sparql'
    try:
        r = requests.get(url, params = {'format': 'json', 'query': query})
        data = r.json()
    except json.JSONDecodeError as e:
        raise Exception('Invalid query')
    
    if ('results' in data) and ('bindings' in data['results']):
        columns = data['head']['vars']
        rows = []
        for binding in data['results']['bindings']:
            row = [convert_datatype(binding[col]) if col in binding else None
                   for col in columns]
            rows.append(row)
    else:
        raise Exception('No results')
    
    return pd.DataFrame(rows, columns=columns)