from bs4 import BeautifulSoup
import requests
def get_pssh(url):
    response = requests.get(url)
    
    content_protections = BeautifulSoup(response.content, features="xml").findAll('ContentProtection')
    
    pssh = []
    for cp in content_protections:
        if cp['schemeIdUri'].lower() == 'urn:uuid:9a04f079-9840-4286-ab92-e65be0885f95':
            p = cp.find('cenc:pssh')
            if p:
                pssh.append(p.text)
                
    return pssh