fix(xlsx): keep integer rendering when blanks promote a column to float

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

@@ -93,6 +93,30 @@ def _repair_sheetview_show_zeroes(
     return repaired_stream
 
 
+def _format_integral_columns(sheet: Any) -> Any:
+    """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]
+        if not pd.api.types.is_float_dtype(series.dtype):
+            continue
+        values = series.dropna()
+        if values.empty or not (values % 1 == 0).all():
+            continue
+        # Object dtype keeps mixed ints and NaN from being coerced back to float.
+        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.
@@ -150,7 +174,7 @@ def convert(
 
             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
@@ -241,7 +265,7 @@ 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 +1,99 @@
+"""Whole numbers must not render as ``1.0`` when a blank promotes the column to float."""
+
+from io import BytesIO
+
+import openpyxl
+import pandas as pd
+
+from markitdown import MarkItDown, StreamInfo
+from markitdown.converters._xlsx_converter import _format_integral_columns
+
+
+def _convert_workbook(workbook: openpyxl.Workbook) -> str:
+    stream = BytesIO()
+    workbook.save(stream)
+    stream.seek(0)
+    return (
+        MarkItDown(enable_plugins=False)
+        .convert_stream(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
+    assert sheet is not None
+    sheet.title = "Sheet"
+    sheet.append(["count"])
+    sheet.append([1])
+    sheet.append([None])
+    sheet.append([2])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "| 1 |" in markdown
+    assert "| 2 |" in markdown
+    assert "1.0" not in markdown
+    assert "2.0" not in markdown
+
+
+def test_integer_column_with_blank_beside_clean_integer_column() -> None:
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    assert sheet is not None
+    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_fractional_numbers_keep_their_decimals() -> None:
+    workbook = openpyxl.Workbook()
+    sheet = workbook.active
+    assert sheet is not None
+    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
+    assert sheet is not None
+    sheet.title = "Sheet"
+    sheet.append(["Qty"])
+    sheet.append([2])
+    sheet.append([4])
+
+    markdown = _convert_workbook(workbook)
+
+    assert "| 2 |" in markdown
+    assert "| 4 |" in markdown
+
+
+def test_format_integral_columns_helper_preserves_fractions_and_empties() -> None:
+    # Shared by both the .xlsx and .xls converters before to_html.
+    sheet = pd.DataFrame({"a": [1.0, None, 2.0], "b": [1.5, None, 2.0]})
+    formatted = _format_integral_columns(sheet.copy())
+
+    assert formatted["a"].tolist()[0] == 1
+    assert formatted["a"].tolist()[2] == 2
+    assert pd.isna(formatted["a"].tolist()[1])
+    assert formatted["b"].tolist()[0] == 1.5
+    assert isinstance(formatted["a"].tolist()[0], int)