feat: cast bools to strings if mixed types

python/tests/test_fastexcel.py

@@ -580,3 +580,16 @@ def test_null_values_in_cells() -> None:
     pd_expected = pd.DataFrame(expected)
     pd_expected["Date"] = pd_expected["Date"].dt.as_unit("ms")
     pd_assert_frame_equal(sheet.to_pandas(), pd_expected)
+
+
+def test_bool_casting_to_string_for_polars() -> None:
+    excel_reader = fastexcel.read_excel(path_for_fixture("sheet-bool.xlsx"))
+
+    actual_polars_df = excel_reader.load_sheet(0, header_row=None, column_names=["0"]).to_polars()
+    expected_polars_df = pl.DataFrame(
+        {
+            "0": ["true", "false", "some string"],
+        }
+    )
+
+    pl_assert_frame_equal(actual_polars_df, expected_polars_df)

src/types/dtype.rs

@@ -224,6 +224,7 @@ fn int_types() -> &'static HashSet<DType> {
 fn string_types() -> &'static HashSet<DType> {
     STRING_TYPES_CELL.get_or_init(|| {
         HashSet::from([
+            DType::Bool,
             DType::Int,
             DType::Float,
             DType::String,

src/types/python/excelsheet/sheet_data.rs

@@ -134,6 +134,8 @@ mod array_impls {
                         .map(|dt| dt.to_string())
                 } else if cell.is_datetime_iso() {
                     cell.get_datetime_iso().map(str::to_string)
+                } else if cell.is_bool() {
+                    cell.get_bool().map(|v| v.to_string())
                 } else {
                     cell.as_string()
                 }