Added type hints

Author: radarhere

.ci/requirements-mypy.txt

@@ -4,6 +4,7 @@ IceSpringPySideStubs-PySide6
 ipython
 numpy
 packaging
+pyarrow-stubs
 pytest
 sphinx
 types-atheris

Tests/test_pyarrow.py

@@ -13,7 +13,11 @@
     is_big_endian,
 )
 
-pyarrow = pytest.importorskip("pyarrow", reason="PyArrow not installed")
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    import pyarrow
+else:
+    pyarrow = pytest.importorskip("pyarrow", reason="PyArrow not installed")
 
 TEST_IMAGE_SIZE = (10, 10)
 
@@ -94,14 +98,14 @@ def _test_img_equals_int32_pyarray(
         ("HSV", fl_uint8_4_type, [0, 1, 2]),
     ),
 )
-def test_to_array(mode: str, dtype: Any, mask: list[int] | None) -> None:
+def test_to_array(mode: str, dtype: pyarrow.DataType, mask: list[int] | None) -> None:
     img = hopper(mode)
 
     # Resize to non-square
     img = img.crop((3, 0, 124, 127))
     assert img.size == (121, 127)
 
-    arr = pyarrow.array(img)
+    arr = pyarrow.array(img)  # type: ignore[call-overload]
     _test_img_equals_pyarray(img, arr, mask)
     assert arr.type == dtype
 
@@ -118,8 +122,8 @@ def test_lifetime() -> None:
 
     img = hopper("L")
 
-    arr_1 = pyarrow.array(img)
-    arr_2 = pyarrow.array(img)
+    arr_1 = pyarrow.array(img)  # type: ignore[call-overload]
+    arr_2 = pyarrow.array(img)  # type: ignore[call-overload]
 
     del img
 
@@ -136,8 +140,8 @@ def test_lifetime2() -> None:
 
     img = hopper("L")
 
-    arr_1 = pyarrow.array(img)
-    arr_2 = pyarrow.array(img)
+    arr_1 = pyarrow.array(img)  # type: ignore[call-overload]
+    arr_2 = pyarrow.array(img)  # type: ignore[call-overload]
 
     assert arr_1.sum().as_py() > 0
     del arr_1
@@ -152,7 +156,7 @@ def test_lifetime2() -> None:
 
 
 class DataShape(NamedTuple):
-    dtype: Any
+    dtype: pyarrow.DataType
     # Strictly speaking, elt should be a pixel or pixel component, so
     # list[uint8][4], float, int, uint32, uint8, etc.  But more
     # correctly, it should be exactly the dtype from the line above.