Simplify the code

Bug fix

Simplify the code

Update basic_calculate.py

Update README.md, simplify some code.

Update README.md

Update README.md

Add many many things.

Add train_mode and eval_mode.

Add weight decay, simplify the code

Edit README.md

Add Dropout, simplify the code.

Add BatchNorm2d and Adam

Edit optimizer

Edit README.md