Yolox code combing

1. Registration class

I was confused at the beginning. The configuration file read is exp/default/yolox_s.py, but this file does not exist. The similar file is exps/default/yolox_s.py. This file exists, but the path and configuration are wrong. I once thought it was a typo. After all, there is not much difference between exp and exps. until I see the content of init.py

First, we configured yolox_s in train.py

and then looked at



this function. First, replace - _ and then combine them together to get module_name=yolox.exp.default.yolox_s
and then import the exp() object of this file. But we did not find this file in this path.

There is only one init.py without yolox_s, but it will go to init.py to execute first, then init.py is the one below

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# Copyright (c) Megvii Inc. All rights reserved.

# This file is used for package installation and find default exp file

import importlib
import sys
from pathlib import Path

_EXP_PATH = Path(__file__).resolve().parent.parent.parent.parent / "exps" / "default"  # 正确的路径

if _EXP_PATH.is_dir():  # 如果这个路径存在
    # This is true only for in-place installation (pip install -e, setup.py develop),
    # where setup(package_dir=) does not work: https://github.com/pypa/setuptools/issues/230

    class _ExpFinder(importlib.abc.MetaPathFinder): 
        
        def find_spec(self, name, path, target=None):  #然后自动执行find_spec方法  name就是传进来的module_name=yolox.exp.default.yolox_s
            if not name.startswith("yolox.exp.default"):
                return 
            project_name = name.split(".")[-1] + ".py"   #最后一个就是yolox_s.py
            target_file = _EXP_PATH / project_name  #路径拼接就是 exps/default/yolox_s.py
            if not target_file.is_file():
                return
            return importlib.util.spec_from_file_location(name, target_file)   然后返回yolox_s.py模块

    sys.meta_path.append(_ExpFinder())  # 就会把这个_expfinder加入字典中

After getting the yolox_s.py module, you can only generate exp() objects

2. The following code is really nothing bright, it is all step by step, boring