fixed type hint (tests would have caught it)

src/awkward/contents/bitmaskedarray.py

@@ -288,7 +288,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> BitMaskedFo
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> BitMaskedForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> BitMaskedForm:
         return self.form_cls(
             self._mask.form,
             self._content._form_with_key_path((*path, None)),

src/awkward/contents/bytemaskedarray.py

@@ -218,7 +218,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> ByteMaskedF
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> ByteMaskedForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> ByteMaskedForm:
         return self.form_cls(
             self._mask.form,
             self._content._form_with_key_path((*path, None)),

src/awkward/contents/content.py

@@ -238,10 +238,10 @@ def _form_with_key(
     ) -> Form:
         raise NotImplementedError
 
-    def form_with_key_path(self, root: (str | None) = ()) -> Form:
+    def form_with_key_path(self, root: (str | int | None) = ()) -> Form:
         return self._form_with_key_path(root)
 
-    def _form_with_key_path(self, path: (str | None)) -> Form:
+    def _form_with_key_path(self, path: (str | int | None)) -> Form:
         raise NotImplementedError
 
     @property

src/awkward/contents/emptyarray.py

@@ -118,7 +118,7 @@ def simplified(cls, *, parameters=None, backend=None):
     def _form_with_key(self, getkey: Callable[[Content], str | None]) -> EmptyForm:
         return self.form_cls(form_key=getkey(self))
 
-    def _form_with_key_path(self, path: (str | None)) -> EmptyForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> EmptyForm:
         return self.form_cls(form_key=repr(path))
 
     def _to_buffers(

src/awkward/contents/indexedarray.py

@@ -214,7 +214,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> IndexedForm
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> IndexedForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> IndexedForm:
         return self.form_cls(
             self._index.form,
             self._content._form_with_key_path((*path, None)),

src/awkward/contents/indexedoptionarray.py

@@ -202,7 +202,7 @@ def _form_with_key(
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> IndexedOptionForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> IndexedOptionForm:
         return self.form_cls(
             self._index.form,
             self._content._form_with_key_path((*path, None)),

src/awkward/contents/listarray.py

@@ -207,7 +207,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> ListForm:
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> ListForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> ListForm:
         return self.form_cls(
             self._starts.form,
             self._stops.form,

src/awkward/contents/listoffsetarray.py

@@ -199,7 +199,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> ListOffsetF
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> ListOffsetForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> ListOffsetForm:
         return self.form_cls(
             self._offsets.form,
             self._content._form_with_key_path((*path, None)),

src/awkward/contents/numpyarray.py

@@ -200,7 +200,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> NumpyForm:
             form_key=getkey(self),
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> NumpyForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> NumpyForm:
         return self.form_cls(
             ak.types.numpytype.dtype_to_primitive(self._data.dtype),
             self.inner_shape,

src/awkward/contents/recordarray.py

@@ -316,7 +316,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> RecordForm:
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> RecordForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> RecordForm:
         if self._fields is None:
             contents = [
                 x._form_with_key_path((*path, i)) for i, x in enumerate(self._contents)

src/awkward/contents/regulararray.py

@@ -211,7 +211,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> RegularForm
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> RegularForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> RegularForm:
         return self.form_cls(
             self._content._form_with_key_path((*path, None)),
             self._size,

src/awkward/contents/unionarray.py

@@ -460,7 +460,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> UnionForm:
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> UnionForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> UnionForm:
         return self.form_cls(
             self._tags.form,
             self._index.form,

src/awkward/contents/unmaskedarray.py

@@ -138,7 +138,7 @@ def _form_with_key(self, getkey: Callable[[Content], str | None]) -> UnmaskedFor
             form_key=form_key,
         )
 
-    def _form_with_key_path(self, path: (str | None)) -> UnmaskedForm:
+    def _form_with_key_path(self, path: (str | int | None)) -> UnmaskedForm:
         return self.form_cls(
             self._content._form_with_key_path((*path, None)),
             parameters=self._parameters,