Adding data to a YAML file using Python

I am trying to write a dictionary value to a YAML file.

The dictate is:

data_dict = {'BACKENDTYPE' :{ 'BACKENDNAME' : 'BACKENDPATH'}}

      

        
        
        
      

    

Update code:

with open(backend_config_file,'w')as yaml_file:
            yaml_file.write(yaml.dump(data_dict , default_flow_style=False))

      

        
        
        
      

    

The problem is it will always overwrite the YAML file and not add the dictionary.

Is there a way to add the data or the data should be treated like the dict itself and the resulting dictionary, fully preserved?