根据字符串当作变量，进行类名转换

#配置文件中数据

PLUGINS = {
    'disk': 'src.plugins.disk.DiskPlugin',
    'mem': 'src.plugins.mem.MemPlugin',
    'nic': 'src.plugins.nic.NicPlugin',
    }
response = {}

for k,v in PLUGINS.items():
    #将类名从字符串分离出来
    file_path,clsname=v.rsplit(".",1)
    file_obj=__import__(file_path,fromlist=clsname)  #方式一
    #import importlib
    #file_obj=importlib.import_module(file_path)  ##方式二
        if hasattr(file_obj,clsname):
            ret=getattr(file_obj,clsname)()
            response[k]=ret.execute("查看平台命令")
         else:      
            raise Exception("配置文件错误")
print(response）
 '''  

期望返回的字典内容： 
response = {
    'disk': "disksadfasdfasdfa",
    'mem': "memasdfasdfasdf",
    'nic': "nicasdfasdfasdfasf",
}

'''


三个py文件：src/plugins/disk.py



```python
class DiskPlugin:
    def execute(self):
            return 'disksadfasdfasdfa'
```

src/plugins/mem.py

```python
class MemPlugin:
    def execute(self):
        return 'memasdfasdfasdf'
```

src/plugins/nic.py

```python
class NicPlugin:
    def execute(self):
    return 'nicasdfasdfasdfasf'
```

src/plugins/nic.py

class NicPlugin:
def execute(self):
return 'nicasdfasdfasdfasf'