improve: introduce isort for linting Python imports (#1983)

api/controllers/service_api/dataset/document.py

@@ -1,24 +1,23 @@
 import json
 
-from flask import request
-from flask_restful import reqparse, marshal
-from flask_login import current_user
-from sqlalchemy import desc
-from werkzeug.exceptions import NotFound
-
 import services.dataset_service
 from controllers.service_api import api
 from controllers.service_api.app.error import ProviderNotInitializeError
-from controllers.service_api.dataset.error import ArchivedDocumentImmutableError, DocumentIndexingError, \
-    NoFileUploadedError, TooManyFilesError
+from controllers.service_api.dataset.error import (ArchivedDocumentImmutableError, DocumentIndexingError,
+                                                   NoFileUploadedError, TooManyFilesError)
 from controllers.service_api.wraps import DatasetApiResource, cloud_edition_billing_resource_check
-from libs.login import current_user
 from core.errors.error import ProviderTokenNotInitError
 from extensions.ext_database import db
 from fields.document_fields import document_fields, document_status_fields
+from flask import request
+from flask_login import current_user
+from flask_restful import marshal, reqparse
+from libs.login import current_user
 from models.dataset import Dataset, Document, DocumentSegment
 from services.dataset_service import DocumentService
 from services.file_service import FileService
+from sqlalchemy import desc
+from werkzeug.exceptions import NotFound
 
 
 class DocumentAddByTextApi(DatasetApiResource):