fix(xlsx): keep integer rendering when a blank cell promotes a column to float

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

@@ -84,6 +84,32 @@ def _repair_sheetview_show_zeroes(
     return repaired_stream
 
 
+def _format_integral_columns(sheet: "pd.DataFrame") -> "pd.DataFrame":
+    """Render whole numbers stored as floats without a trailing ``.0``.
+
+    A single blank cell makes pandas read the column as float64, so every
+    whole number in it renders as ``1.0`` even though Excel shows ``1``.
+    Columns whose present values are all whole numbers are converted back to
+    integers for display; fractional values and missing cells are unchanged.
+    """
+    for column in sheet.columns:
+        series = sheet[column]
+        values = series.dropna()
+        if (
+            pd.api.types.is_float_dtype(series.dtype)
+            and not values.empty
+            and (values % 1 == 0).all()
+        ):
+            # The object dtype stops pandas from coercing the mixed ints and
+            # NaN values back into a float column on assignment.
+            sheet[column] = pd.Series(
+                [int(value) if pd.notna(value) else value for value in series],
+                dtype=object,
+                index=series.index,
+            )
+    return sheet
+
+
 class XlsxConverter(DocumentConverter):
     """
     Converts XLSX files to Markdown, with each sheet presented as a separate Markdown table.
@@ -135,7 +161,7 @@ def convert(
         md_content = ""
         for s in sheets:
             md_content += f"## {s}\n"
-            html_content = sheets[s].to_html(index=False)
+            html_content = _format_integral_columns(sheets[s]).to_html(index=False)
             md_content += (
                 self._html_converter.convert_string(
                     html_content, **kwargs
@@ -197,7 +223,7 @@ def convert(
         md_content = ""
         for s in sheets:
             md_content += f"## {s}\n"
-            html_content = sheets[s].to_html(index=False)
+            html_content = _format_integral_columns(sheets[s]).to_html(index=False)
             md_content += (
                 self._html_converter.convert_string(
                     html_content, **kwargs

packages/markitdown/tests/test_xlsx_number_formatting.py

@@ -0,0 +1,80 @@
+from io import BytesIO
+
+import openpyxl
+
+from markitdown import MarkItDown, StreamInfo
+
+
+def _convert_workbook(workbook: openpyxl.Workbook) -> str:
+    stream = BytesIO()
+    workbook.save(stream)
+    stream.seek(0)
+    return MarkItDown().convert(
+        stream, stream_info=StreamInfo(extension=".xlsx")
+    ).markdown
+
+
+def test_integer_column_with_blank_cell_renders_without_trailing_point_zero() -> None:
+    # A blank cell makes pandas read the column as float64, which used to
+    # render every whole number in it as "1.0" even though Excel shows "1".
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    sheet.title = "Sheet"
+    sheet.append(["Qty", "Note"])
+    sheet.append([1, "first"])
+    sheet.append([None, "gap"])
+    sheet.append([3, "last"])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "| 1 | first |" in markdown
+    assert "| 3 | last |" in markdown
+    assert "1.0" not in markdown
+    assert "3.0" not in markdown
+
+
+def test_integer_column_with_numeric_header_and_blank_cell() -> None:
+    # A numeric header row (e.g. years) keeps the column numeric even before
+    # the header is split off, so the whole column is read as float64 and
+    # its data cells used to render as "1.0" beside clean "5" cells.
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    sheet.title = "Sheet"
+    sheet.append([2023, 2024])
+    sheet.append([1, 5])
+    sheet.append([None, 6])
+    sheet.append([3, 7])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "| 1 | 5 |" in markdown
+    assert "| 3 | 7 |" in markdown
+    assert "1.0" not in markdown
+    assert "3.0" not in markdown
+
+
+def test_fractional_numbers_keep_their_decimals() -> None:
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    sheet.title = "Sheet"
+    sheet.append(["Price"])
+    sheet.append([2.5])
+    sheet.append([None])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "2.5" in markdown
+
+
+def test_fully_populated_integer_column_is_unchanged() -> None:
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    sheet.title = "Sheet"
+    sheet.append(["Qty"])
+    sheet.append([2])
+    sheet.append([4])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "| 2 |" in markdown
+    assert "| 4 |" in markdown