# ModelArts导入模型时，如何编写模型配置文件中的安装包依赖参数？
#### 问题描述
从OBS中或者从容器镜像中导入模型时，开发者需要编写模型配置文件。模型配置文件描述模型用途、模型计算框架、模型精度、推理代码依赖包以及模型对外API接口。配置文件为JSON格式。配置文件中的"dependencies"，表示配置模型推理代码需要的依赖包，需要提供依赖包名、安装方式和版本约束的信息，详细参数见[模型配置文件编写说明](https://support.huaweicloud.com/usermanual-standard-modelarts/inference-modelarts-0056.html)。导入模型时，模型配置文件中的安装包依赖参数"dependencies"如何编写？
#### 解决方案
安装包存在前后依赖关系。例如您在安装"mmcv-full"之前，需要完成"Cython"、"pytest-runner"、"pytest"的安装，在配置文件中，您需要把"Cython"、"pytest-runner"、"pytest"写在"mmcv-full"的前面。
示例如下：
```
"dependencies": [
    {
    "installer": "pip",
    "packages": [
        {
            "package_name": "Cython"
        },
        {
            "package_name": "pytest-runner"
        },
        {
            "package_name": "pytest"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "5.0.0",
            "package_name": "Pillow"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.4.0",
            "package_name": "torch"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.19.1",
            "package_name": "numpy"
        },
        {
            "package_name": "mmcv-full"
        }
      ]
   }
]
```
当"mmcv-full"安装失败，原因可能是基础镜像中没有安装gcc，无法编译导致安装失败，此时需要用户使用线下wheel包安装。
示例如下：
```
"dependencies": [
    {
    "installer": "pip",
    "packages": [
        {
            "package_name": "Cython"
        },
        {
            "package_name": "pytest-runner"
        },
        {
            "package_name": "pytest"
        }, 
        {
            "restraint": "ATLEAST",
            "package_version": "5.0.0",
            "package_name": "Pillow"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.4.0",
            "package_name": "torch"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.19.1",
            "package_name": "numpy"
        },
        {
            "package_name": "mmcv_full-1.3.9-cp37-cp37m-manylinux1_x86_64.whl"
        }
      ]
    }
]
```
模型配置文件的"dependencies"支持多个"dependency"结构数组以list形式填入。
示例如下：
```
"dependencies": [
    {
    "installer": "pip",
    "packages": [
        {
            "package_name": "Cython"
        },
        {
            "package_name": "pytest-runner"
        },
        {
            "package_name": "pytest"
        }, 
        {
            "package_name": "mmcv_full-1.3.9-cp37-cp37m-manylinux1_x86_64.whl"
        }
      ]
    },
    {
    "installer": "pip",
    "packages": [
        {
            "restraint": "ATLEAST",
            "package_version": "5.0.0",
            "package_name": "Pillow"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.4.0",
            "package_name": "torch"
        },
        {
            "restraint": "ATLEAST",
            "package_version": "1.19.1",
            "package_name": "numpy"
        },
      ]
    }
]
```