Error with https://www.pythonprogramming.in/classes-and-objects.html

exception = HTTPSConnectionPool(host='www.pythonprogramming.in', port=443): Max retries exceeded with url: /classes-and-objects.html (Caused by SSLError(SSLCertVerificationError(1, "[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: Hostname mismatch, certificate is not valid for 'www.pythonprogramming.in'. (_ssl.c:992)")))