How to check if 2 urls in same domain?

Question

I was trying to check if 2 urls have same domain using prase.urlparse like this:

if parse.urlparse(url1).hostname == parse.urlparse(url2).hostname:
    print('Same Domain')
else:
    print('Different Domain')

While this works for: https://example.com/page1 and https://example.com/page1

it doesn't work for: https://sub1.example.com/page1 and https://sub2.example.com/page1

As the returned hostname for first url is sub1.example.com and for second url is https://sub2.example.com/page1...

What if I only care about main domain and not subdomains?

I want to retrive example.com alone without manually parsing the url as a string but rather use libraries for such cases like parse.urlprase.