Fix: lazy load Notion loader (#419)

embedchain/data_formatter/data_formatter.py

@@ -11,7 +11,6 @@ from embedchain.loaders.docs_site_loader import DocsSiteLoader
 from embedchain.loaders.docx_file import DocxFileLoader
 from embedchain.loaders.local_qna_pair import LocalQnaPairLoader
 from embedchain.loaders.local_text import LocalTextLoader
-from embedchain.loaders.notion import NotionLoader
 from embedchain.loaders.pdf_file import PdfFileLoader
 from embedchain.loaders.sitemap import SitemapLoader
 from embedchain.loaders.web_page import WebPageLoader
@@ -46,10 +45,16 @@ class DataFormatter:
             "docx": DocxFileLoader(),
             "sitemap": SitemapLoader(),
             "docs_site": DocsSiteLoader(),
-            "notion": NotionLoader(),
         }
+        lazy_loaders = ("notion", )
         if data_type in loaders:
             return loaders[data_type]
+        elif data_type in lazy_loaders:
+            if data_type == "notion":
+                from embedchain.loaders.notion import NotionLoader
+                return NotionLoader()
+            else:
+                raise ValueError(f"Unsupported data type: {data_type}")
         else:
             raise ValueError(f"Unsupported data type: {data_type}")