fix(python): Validate pl.Array shape argument types (#20915)

Author: FBruzzesi

Diff for: py-polars/polars/datatypes/classes.py

@@ -813,7 +813,7 @@ def __init__(
             self.size = shape
             self.shape = (shape,) + inner_shape
 
-        elif isinstance(shape, tuple):
+        elif isinstance(shape, tuple) and isinstance(shape[0], int):  # type: ignore[redundant-expr]
             if len(shape) > 1:
                 inner_parsed = Array(inner_parsed, shape[1:])
 

Diff for: py-polars/tests/unit/datatypes/test_array.py

@@ -329,6 +329,11 @@ def test_array_missing_shape() -> None:
         pl.Array(pl.Int8)
 
 
+def test_array_invalid_shape_type() -> None:
+    with pytest.raises(TypeError, match="invalid input for shape"):
+        pl.Array(pl.Int8, shape=("x",))  # type: ignore[arg-type]
+
+
 def test_array_invalid_physical_type_18920() -> None:
     s1 = pl.Series("x", [[1000, 2000]], pl.List(pl.Datetime))
     s2 = pl.Series("x", [None], pl.List(pl.Datetime))