code: def delete(self, file_id):
          
          return defer.DeferredList([
              self.__files.remove({"_id": file_id}, safe=True),
              self.__chunks.remove({"files_id": file_id})
          ])
docs: Delete a file from GridFS by ``"_id"``.
  
          Removes all data belonging to the file with ``"_id"``:
          `file_id`.
  
          .. warning:: Any processes/threads reading from the file while
             this method is executing will likely see an invalid/corrupt
             file. Care should be taken to avoid concurrent reads to a file
             while it is being deleted.
  
          :Parameters:
            - `file_id`: ``"_id"`` of the file to delete
  
          .. versionadded:: 1.6