feat(exp,tools): support installation for pip (#1020)

README.md

@@ -120,22 +120,23 @@ ln -s /path/to/your/COCO ./datasets/COCO
 Step2. Reproduce our results on COCO by specifying -n:
 
 ```shell
-python tools/train.py -n yolox-s -d 8 -b 64 --fp16 -o [--cache]
-                         yolox-m
-                         yolox-l
-                         yolox-x
+python -m yolox.tools.train -n yolox-s -d 8 -b 64 --fp16 -o [--cache]
+                               yolox-m
+                               yolox-l
+                               yolox-x
 ```
 * -d: number of gpu devices
 * -b: total batch size, the recommended number for -b is num-gpu * 8
 * --fp16: mixed precision training
 * --cache: caching imgs into RAM to accelarate training, which need large system RAM. 
 
+  
 When using -f, the above commands are equivalent to:
 ```shell
-python tools/train.py -f exps/default/yolox_s.py -d 8 -b 64 --fp16 -o [--cache]
-                         exps/default/yolox_m.py
-                         exps/default/yolox_l.py
-                         exps/default/yolox_x.py
+python -m yolox.tools.train -f exps/default/yolox_s.py -d 8 -b 64 --fp16 -o [--cache]
+                               exps/default/yolox_m.py
+                               exps/default/yolox_l.py
+                               exps/default/yolox_x.py
 ```
   
 **Multi Machine Training**
@@ -154,6 +155,12 @@ On the second machine, run
 python tools/train.py -n yolox-s -b 128 --dist-url tcp://123.123.123.123:12312 --num-machines 2 --machine-rank 1
 ```
 
+**Others**  
+See more information with the following command:
+```shell
+python -m yolox.tools.train --help
+```
+  
 </details>
 
 
@@ -163,10 +170,10 @@ python tools/train.py -n yolox-s -b 128 --dist-url tcp://123.123.123.123:12312 -
 We support batch testing for fast evaluation:
 
 ```shell
-python tools/eval.py -n  yolox-s -c yolox_s.pth -b 64 -d 8 --conf 0.001 [--fp16] [--fuse]
-                         yolox-m
-                         yolox-l
-                         yolox-x
+python -m yolox.tools.eval -n  yolox-s -c yolox_s.pth -b 64 -d 8 --conf 0.001 [--fp16] [--fuse]
+                               yolox-m
+                               yolox-l
+                               yolox-x
 ```
 * --fuse: fuse conv and bn
 * -d: number of GPUs used for evaluation. DEFAULT: All GPUs available will be used.
@@ -174,10 +181,10 @@ python tools/eval.py -n  yolox-s -c yolox_s.pth -b 64 -d 8 --conf 0.001 [--fp16]
 
 To reproduce speed test, we use the following command:
 ```shell
-python tools/eval.py -n  yolox-s -c yolox_s.pth -b 1 -d 1 --conf 0.001 --fp16 --fuse
-                         yolox-m
-                         yolox-l
-                         yolox-x
+python -m yolox.tools.eval -n  yolox-s -c yolox_s.pth -b 1 -d 1 --conf 0.001 --fp16 --fuse
+                               yolox-m
+                               yolox-l
+                               yolox-x
 ```
 
 </details>

yolox/exp/build.py

@@ -18,24 +18,13 @@ def get_exp_by_file(exp_file):
 
 
 def get_exp_by_name(exp_name):
-    import yolox
-
-    yolox_path = os.path.dirname(os.path.dirname(yolox.__file__))
-    filedict = {
-        "yolox-s": "yolox_s.py",
-        "yolox-m": "yolox_m.py",
-        "yolox-l": "yolox_l.py",
-        "yolox-x": "yolox_x.py",
-        "yolox-tiny": "yolox_tiny.py",
-        "yolox-nano": "nano.py",
-        "yolov3": "yolov3.py",
-    }
-    filename = filedict[exp_name]
-    exp_path = os.path.join(yolox_path, "exps", "default", filename)
-    return get_exp_by_file(exp_path)
-
-
-def get_exp(exp_file, exp_name):
+    exp = exp_name.replace("-", "_")  # convert string like "yolox-s" to "yolox_s"
+    module_name = ".".join(["yolox", "exp", "default", exp])
+    exp_object = importlib.import_module(module_name).Exp()
+    return exp_object
+
+
+def get_exp(exp_file=None, exp_name=None):
     """
     get Exp object by file or name. If exp_file and exp_name
     are both provided, get Exp by exp_file.

yolox/exp/default/__init__.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+# -*- coding:utf-8 -*-
+# Copyright (c) 2014-2021 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"
+
+if _EXP_PATH.is_dir():
+    # 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):
+            if not name.startswith("yolox.exp.default"):
+                return
+            project_name = name.split(".")[-1] + ".py"
+            target_file = _EXP_PATH / project_name
+            if not target_file.is_file():
+                return
+            return importlib.util.spec_from_file_location(name, target_file)
+
+    sys.meta_path.append(_ExpFinder())

yolox/tools/__init__.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+# -*- coding:utf-8 -*-
+# Copyright (c) 2014-2021 Megvii Inc. All rights reserved.
+
+# This file is used for package installation. Script of train/eval/export will be available.
+
+import importlib
+import sys
+from pathlib import Path
+
+_TOOLS_PATH = Path(__file__).resolve().parent.parent.parent / "tools"
+
+if _TOOLS_PATH.is_dir():
+    # 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 _PathFinder(importlib.abc.MetaPathFinder):
+
+        def find_spec(self, name, path, target=None):
+            if not name.startswith("yolox.tools."):
+                return
+            project_name = name.split(".")[-1] + ".py"
+            target_file = _TOOLS_PATH / project_name
+            if not target_file.is_file():
+                return
+            return importlib.util.spec_from_file_location(name, target_file)
+
+    sys.meta_path.append(_PathFinder())