pytorch扩展

python

__init__.py

导入包时实际导入的是__init__.py，可以通过__init__.py来控制可以使用的包和函数。
__all__关键字可以方便得用来指定要导入的包。

ctypes

cffi的wraper

cffi

pytorch

c文件

需要一个h文件

python文件

build so

ffi.create_extension和build

扩展autograd

需要init forward 和 backward
tensor和variable的函数基本一样
function的属性
Attributes:
saved_tensors: Tuple of Tensors that were saved in the call to
:func:forward.
saved_variables: Tuple of Variables that correspond to the tensors
saved in the call to :func:forward.
needs_input_grad: Tuple of booleans of length :attr:num_inputs,
indicating whether a given input requires gradient. This can be
used to optimize buffers saved for backward, and ignoring gradient
computation in :func:~Function.backward.
num_inputs: Number of inputs given to :func:forward.
num_outputs: Number of tensors returned by :func:forward.
requires_grad: Boolean indicating whether the :func:backward will
ever need to be called.

扩展nn

modules版本

可以保存参数
需要init（用于初始化参数） forward（调用autograd即可）

functional版本