did you consider to pass in the server URL you're after to select out the server, e.g:
def get_server(url)
portal_url="https://spt.gis.com/arcgis"
portal_username="portaladmin"
portal_password="adminpassword"
gis = GIS(portal_url, portal_username, portal_password,verify_cert=False)
my_servers =gis.admin.servers.list()
for server in my_servers:
print(server.url)
if server.url==url:
print("hi,we're here")