fix: keep blank cells blank and NA-like text intact in XLSX/XLS

packages/markitdown/src/markitdown/converters/_xlsx_converter.py

@@ -52,12 +52,19 @@ def _read_xlsx_sheets(
     repaired_stream = None
     try:
         try:
-            sheets = pd.read_excel(file_stream, sheet_name=None, engine="openpyxl")
+            sheets = pd.read_excel(
+                file_stream, sheet_name=None, engine="openpyxl", keep_default_na=False
+            )
         except TypeError as exc:
             if "showZeroes" not in str(exc):
                 raise
             repaired_stream = _repair_sheetview_show_zeroes(file_stream, start_pos)
-            sheets = pd.read_excel(repaired_stream, sheet_name=None, engine="openpyxl")
+            sheets = pd.read_excel(
+                repaired_stream,
+                sheet_name=None,
+                engine="openpyxl",
+                keep_default_na=False,
+            )
         yield sheets, repaired_stream if repaired_stream is not None else file_stream
     finally:
         if repaired_stream is not None:
@@ -237,7 +244,9 @@ def convert(
                 _xls_dependency_exc_info[2]
             )
 
-        sheets = pd.read_excel(file_stream, sheet_name=None, engine="xlrd")
+        sheets = pd.read_excel(
+            file_stream, sheet_name=None, engine="xlrd", keep_default_na=False
+        )
         md_content = ""
         for s in sheets:
             md_content += f"## {s}\n"

packages/markitdown/tests/test_xlsx.py

@@ -542,3 +542,22 @@ def test_xlsx_show_zeroes_rename_is_scoped_to_sheet_view_tags() -> None:
 
 if __name__ == "__main__":
     raise SystemExit(pytest.main([__file__]))
+
+
+def test_xlsx_blank_cells_and_na_like_text_are_preserved() -> None:
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    sheet.append(["country", "code", "score"])
+    sheet.append(["Namibia", "NA", 1])
+    sheet.append(["Unknown", "N/A", None])
+    sheet.append(["Other", "null", 2])
+    stream = io.BytesIO()
+    workbook.save(stream)
+    stream.seek(0)
+
+    markdown = MarkItDown().convert_stream(stream, file_extension=".xlsx").markdown
+
+    assert "NaN" not in markdown
+    assert "| Namibia | NA | 1 |" in markdown
+    assert "| Unknown | N/A |  |" in markdown
+    assert "| Other | null | 2 |" in markdown