TensorFlow Federated 0.55.0

Release 0.55.0

Major Features and Improvements

• Removed nest_asyncio dependency from tutorials.
• Added a new
  aggregatorrtff.aggregators.DifferentiallyPrivateFactory.tree_adaptive for
  combining DP-FTRL (https://arxiv.org/abs/2103.00039) and adaptive clipping
  (https://arxiv.org/abs/1905.03871).
• Updated tff.learning.programs.EvaluationManager to set the evaluation
  deadline from the start time.

Breaking Changes

• Python runtime deleted; C++ runtime covers all known use-cases.

Bug Fixes

• Fixed a bug attempting to push tf.data.Dataset iterator ops onto GPUs.