使用Python爬虫抓取PubChem化合物CAS

import pandas as pd 
import numpy as np  
import json 
import requests 
import time 
 
 #%reset -f 
cid = 5280535

 
#url = f'https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/{cid}/JSON/?heading=Chemical+and+Physical+Properties' 
url = f'https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/{cid}/JSON/?heading=Names+and+Identifiers' 
req = requests.get(url) 
req 
 
proper_json = json.loads(req.text) 

proper_json['Record']['Reference'][0]['SourceID']