Fix return type of _Element.iter* methods (GH-70)

These methods return `Iterator` objects, not just `Iterable`s.

Author: Wuestengecko

lxml-stubs/etree.pyi

@@ -166,14 +166,14 @@ class _Element(Iterable["_Element"], Sized):
     def items(self) -> Sequence[Tuple[_AnyStr, _AnyStr]]: ...
     def iter(
         self, tag: Optional[_TagSelector] = ..., *tags: _TagSelector
-    ) -> Iterable[_Element]: ...
+    ) -> Iterator[_Element]: ...
     iterancestors = iter
     def iterchildren(
         self,
         tag: Optional[_TagSelector] = ...,
         reversed: bool = False,
         *tags: _TagSelector,
-    ) -> Iterable[_Element]: ...
+    ) -> Iterator[_Element]: ...
     iterdescendants = iter
     def iterfind(
         self, path: str, namespaces: Optional[_NSMapArg] = ...
@@ -183,13 +183,13 @@ class _Element(Iterable["_Element"], Sized):
         tag: Optional[_TagSelector] = ...,
         preceding: bool = False,
         *tags: _TagSelector,
-    ) -> Iterable[_Element]: ...
+    ) -> Iterator[_Element]: ...
     def itertext(
         self,
         tag: Optional[_TagSelector] = ...,
         with_tail: bool = False,
         *tags: _TagSelector,
-    ) -> Iterable[_AnyStr]: ...
+    ) -> Iterator[_AnyStr]: ...
     def keys(self) -> Sequence[_AnyStr]: ...
     def makeelement(
         self,
@@ -242,7 +242,7 @@ class _ElementTree:
     def getroot(self) -> _Element: ...
     def iter(
         self, tag: Optional[_TagSelector] = ..., *tags: _TagSelector
-    ) -> Iterable[_Element]: ...
+    ) -> Iterator[_Element]: ...
     def iterfind(
         self, path: str, namespaces: Optional[_NSMapArg] = ...
     ) -> Iterator["_Element"]: ...

test-data/test-etree.yml

@@ -34,9 +34,9 @@
     main: |
         from lxml import etree
         element = etree.Element("foo")
-        reveal_type(element.iterchildren)  # N: Revealed type is "def (tag: Union[builtins.str, builtins.bytes, lxml.etree.QName, Any, None] =, reversed: builtins.bool =, *tags: Union[builtins.str, builtins.bytes, lxml.etree.QName, Any]) -> typing.Iterable[lxml.etree._Element]"
+        reveal_type(element.iterchildren)  # N: Revealed type is "def (tag: Union[builtins.str, builtins.bytes, lxml.etree.QName, Any, None] =, reversed: builtins.bool =, *tags: Union[builtins.str, builtins.bytes, lxml.etree.QName, Any]) -> typing.Iterator[lxml.etree._Element]"
         result = element.iterchildren("my-attr")
-        reveal_type(result)  # N: Revealed type is "typing.Iterable[lxml.etree._Element]"
+        reveal_type(result)  # N: Revealed type is "typing.Iterator[lxml.etree._Element]"
 
 -   case: etree_xmlparser_makeelement
     disable_cache: true