gh-130120: Prevent str(zipfile.Path) from raising exception on io.BytesIO-input

Lib/test/test_zipfile/_path/test_path.py

@@ -454,9 +454,15 @@ def test_root_unnamed(self, alpharep):
 
         # .name and .parent should still work on subs
         sub = root / "b"
-        assert sub.name == "b"
+        self.assertEqual(sub.name, "b")
         assert sub.parent
 
+        # It should be possible to get the repr and str
+        self.assertEqual(str(root), ":memory:/")
+        self.assertEqual(repr(root), "Path(None, '')")
+        self.assertEqual(str(sub), ":memory:/b/")
+        self.assertEqual(repr(sub), "Path(None, 'b/')")
+
     @pass_alpharep
     def test_match_and_glob(self, alpharep):
         root = zipfile.Path(alpharep)

Lib/zipfile/_path/__init__.py

@@ -430,7 +430,9 @@ def relative_to(self, other, *extra):
         return posixpath.relpath(str(self), str(other.joinpath(*extra)))
 
     def __str__(self):
-        return posixpath.join(self.root.filename, self.at)
+        if (filename := self.root.filename) is None:
+            filename = ":memory:"
+        return posixpath.join(filename, self.at)
 
     def __repr__(self):
         return self.__repr.format(self=self)

Misc/NEWS.d/next/Library/2025-02-20-21-30-41.gh-issue-130120.-O2xJr.rst

@@ -0,0 +1 @@
+Fix bug where ``str(zipfile.Path(zipfile.ZipFile(io.BytesIO(data))))`` would raise a ``TypeError``