The classes in s104.api can be accessed by just importing s104. They are automatically imported but can be brought in separately if desired.:
from s100py import s104
s104.s104File(...)
# or
from s100py.s104 import api
api.s104File(...)
# or
from s100py import s104.api
s104.api.s104File(...)s100py.s104.v1_1.api