Pytorch is an open source library for Tensors and Dynamic neural networks in Python with strong GPU acceleration. For details, see

PyTorch is a python package that provides two high-level features:

-Tensor computation (like numpy) with strong GPU acceleration

-Deep Neural Networks built on a tape-based autodiff system

Pytorch is an alternative to other deep learning libraries like Tensorflow and Theano with an emphasis on 'Python First' Imperative Programming, designed to be familiar to users for faster development iterations.