Session is the context to use computing, storage and federation resouraces.
At most situation, users should not concern how Session is create.
FATE-Flow is responsed to create and init Session when Task launched.
For those who want to use computing, storage and federation api outside FATE-Flow Task,
flowing is a short guide.
init Session
sess = Session()
sess.as_global()
# flowing is optional, call if needed
# init computing
sess.init_computing(...)
# init federation
sess.init_federation(...)
# init federation
sess.init_storage(...)
computing = sess.computing
federation = sess.federation
storage = sess.storage
computing api has a shortcut
from fate_arch.session import computing_session
computing_session.init(...)
computing_session.parallelize(...)