diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index d94bafc4..c6343310 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -32,13 +32,24 @@ jobs:
           poetry config virtualenvs.create false
           poetry install
 
+      - name: List installed packages
+        run: |
+          poetry run pip list
+
+      - name: Print Sphinx version
+        run: |
+          poetry run sphinx-build --version
+
       - name: Build documentation
         run: |
-          sphinx-build -b html ./docs/source/ ./docs/build/ -v
-          ls -l ./docs/build/  # List output files for debugging
+          echo "Python path before Sphinx build: $PYTHONPATH"
+          poetry run sphinx-build -b html ./docs/source/ ./docs/build/ -vvv
+          echo "Listing built documentation:"
+          ls -l ./docs/build/
 
       - name: Create .nojekyll file
-        run: touch ./docs/build/.nojekyll
+        run: |
+          touch ./docs/build/.nojekyll
 
       - name: Deploy to GitHub Pages
         uses: peaceiris/actions-gh-pages@v3
diff --git a/lightrag/components/data_process/text_splitter.py b/lightrag/components/data_process/text_splitter.py
index 721f3630..2f632c1b 100644
--- a/lightrag/components/data_process/text_splitter.py
+++ b/lightrag/components/data_process/text_splitter.py
@@ -173,8 +173,7 @@ def __init__(
         super().__init__()
 
         self.split_by = split_by
-        options = ", ".join(f"'{key}'" for key in SEPARATORS.keys())
-        assert split_by in SEPARATORS, f"Invalid options for split_by. You must select from {options}."
+        assert split_by in SEPARATORS, f"Invalid options for split_by. You must select from {list(SEPARATORS.keys())}."
         
         assert chunk_overlap < chunk_size, f"chunk_overlap can't be larger than or equal to chunk_size. Received chunk_size: {chunk_size}, chunk_overlap: {chunk_overlap}"