Function is_same_domain

django/utils/http.py:225–242

Return ``True`` if the host is either an exact match or a match to the wildcard pattern. Any pattern beginning with a period matches a domain and all of its subdomains. (e.g. ``.example.com`` matches ``example.com`` and ``foo.example.com``). Anything else is an exact string mat

(host, pattern)

def is_same_domain(host, pattern):
    """
    Return ``True`` if the host is either an exact match or a match
    to the wildcard pattern.

    Any pattern beginning with a period matches a domain and all of its
    subdomains. (e.g. ``.example.com`` matches ``example.com`` and
    ``foo.example.com``). Anything else is an exact string match.
    """
    if not pattern:
        return False

    pattern = pattern.lower()
    return (
        pattern[0] == "."
        and (host.endswith(pattern) or host == pattern[1:])
        or pattern == host
    )


def url_has_allowed_host_and_scheme(url, allowed_hosts, require_https=False):