[Feature] Support for installing mmengine without opencv (#1429)

Author: fanqiNO1

Diff for: .github/workflows/deploy.yml

@@ -26,3 +26,24 @@ jobs:
         run: |
           pip install twine
           twine upload dist/* -u __token__ -p ${{ secrets.pypi_password }}
+
+  build-n-publish-lite:
+    runs-on: ubuntu-latest
+    if: startsWith(github.event.ref, 'refs/tags')
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python 3.7
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+      - name: Install torch
+        run: pip install torch
+      - name: Install wheel
+        run: pip install wheel
+      - name: Build MMEngine-lite
+        run: sed -i "s/os.getenv('MMENGINE_LITE', '0')/os.getenv('MMENGINE_LITE', '1')/g" setup.py
+             python setup.py sdist bdist_wheel
+      - name: Publish distribution to PyPI
+        run: |
+          pip install twine
+          twine upload dist/* -u __token__ -p ${{ secrets.pypi_password }}

Diff for: docs/en/get_started/installation.md

@@ -27,10 +27,10 @@
 ## Install MMEngine
 
 :::{note}
-If you only want to use the fileio, registry, and config modules in MMEngine, you can set the `MMENGINE_LITE` environment variable, which will only install the few third-party library dependencies that are necessary (e.g., it will not install opencv, matplotlib):
+If you only want to use the fileio, registry, and config modules in MMEngine, you can install `mmengine-lite`, which will only install the few third-party library dependencies that are necessary (e.g., it will not install opencv, matplotlib):
 
 ```bash
-MMENGINE_LITE=1 pip install mmengine
+pip install mmengine-lite
 ```
 
 :::

Diff for: docs/zh_cn/get_started/installation.md

@@ -27,10 +27,10 @@
 ## 安装 MMEngine
 
 :::{note}
-如果你只想使用 MMEngine 中的 fileio、registry 和 config 模块，你可以设置 `MMENGINE_LITE` 环境变量，它只会安装必须的几个第三方库依赖（例如不会安装 opencv、matplotlib）：
+如果你只想使用 MMEngine 中的 fileio、registry 和 config 模块，你可以安装`mmengine-lite`，它只会安装必须的几个第三方库依赖（例如不会安装 opencv、matplotlib）：
 
 ```bash
-MMENGINE_LITE=1 pip install mmengine
+pip install mmengine-lite
 ```
 
 :::

Diff for: setup.py

@@ -126,7 +126,8 @@ def gen_packages_items():
             install_requires.append(choose_requirement(main, secondary))
 
 setup(
-    name='mmengine',
+    name='mmengine'
+    if os.getenv('MMENGINE_LITE', '0') == '0' else 'mmengine-lite',
     version=get_version(),
     description='Engine of OpenMMLab projects',
     long_description=readme(),