[AI] "Hands-on Learning-Deep Learning-PyTorch Edition" Notes (2): Accompanying book source code and ipynb preview, mathematical symbols

Summary of AI Learning Catalog

1. Accompanying book source code and ipynb directory

1.1 download

If you haven't downloaded it yet, please refer to: [AI] "Hands-on Learning-Deep Learning-PyTorch Edition" Notes (1): Learning Environment Configuration

1.2 root directory

d2l-zh contains explanations of four frameworks: mxnet, paddle, pytorch, tensorflow

d2l-zh$ tree -L 1
.
├── mxnet
├── paddle
├── pytorch
└── tensorflow

1.3 pytorch directory listing

d2l-zh/pytorch$ tree -L 1
.
├──