is this host a wms or a csw service?

iscsw.py

from owslib import csw

def iscsw(url):
    success = False
    try:
        s = csw.CatalogueServiceWeb(url)
        success = isinstance(s.operations, list) and len(s.operations) > 0
    except:
        pass
    if not success and "?" in url:
        parts = url.split("?", 1)
        url = parts[0]
        success = iscsw(url)
    if not success and not url.endswith("/csw"):
        parts = url.split("?", 1)
        url = parts[0]
        url = url.rstrip("/") + "/csw"
        success = iscsw(url)
    return success

if __name__ == '__main__':
    assert iscsw("http://www.nationaalgeoregister.nl/geonetwork/srv/eng/csw")
    assert iscsw("http://www.nationaalgeoregister.nl/geonetwork/srv/eng/")
    assert not iscsw("http://grid1.wdcb.ru/cgi-bin/mapserv?map=/var/www/html/mapFiles/maingis.map")
    assert not iscsw("http://www.google.com")

iswms.py

from owslib import wms

def iswms(url):
    try:
        s = wms.WebMapService(url)
        return isinstance(s.contents, dict) and s.contents != {}
    except:
        pass
    return False

if __name__ == '__main__':
    assert iswms("http://grid1.wdcb.ru/cgi-bin/mapserv?map=/var/www/html/mapFiles/maingis.map")
    assert not iswms("http://www.google.com/")