improves handling of incorrect types passed to Document.__get_item().

(FIXES: pymupdf#2961)

src/__init__.py

@@ -2546,6 +2546,7 @@ def __exit__(self, *args):
         self.close()
 
     def __getitem__(self, i: int =0):
+        assert isinstance(i, int) or (isinstance(i, tuple) and len(i) == 2 and all(isinstance(x, int) for x in i))
         if i not in self:
             raise IndexError(f"page {i} not in document")
         return self.load_page(i)

src_classic/fitz_old.i

@@ -4800,6 +4800,7 @@ if basestate:
 
 
             def __getitem__(self, i: int =0)->"Page":
+                assert isinstance(i, int) or (isinstance(i, tuple) and len(i) == 2 and all(isinstance(x, int) for x in i))
                 if i not in self:
                     raise IndexError("page not in document")
                 return self.load_page(i)

tests/test_pixmap.py

@@ -11,6 +11,7 @@
 import platform
 import sys
 import tempfile
+import pytest
 
 scriptdir = os.path.abspath(os.path.dirname(__file__))
 epub = os.path.join(scriptdir, "resources", "Bezier.epub")
@@ -132,3 +133,10 @@ def test_2369():
         img_bytes = img["image"]
         fitz.Pixmap(img_bytes)
 
+def test_page_idx_int():
+    doc = fitz.open(pdf)
+    with pytest.raises(AssertionError):
+        doc["0"]
+    assert doc[0]
+    assert doc[(0,0)]
+