PyTorch

Speaking of Deep Learning's library Tensorflow is famous. Since it was released a year and a half ago, I got a name recognition for a moment.
I began looking for other libraries, thinking that it would be better to use a more flexible library than Keras. Then what is Torch's Python version out there!
DeepMind has moved from Torch to Tensorflow, but I anticipate that you are already using PyTorch. Facebook is also one of the representative companies using Torch, and I am involved in the development of PyTorch.