Teach pytype that zip is actually a class.

This has been the case since Python 3.0.

PiperOrigin-RevId: 605122089

pytype/stubs/builtins/builtins.pytd

@@ -172,21 +172,37 @@ def sum(iterable: Iterable[_T], start: _T) -> _T: ...
 def vars(*args, **kwargs) -> dict[str, Any]: ...
 
 if sys.version_info >= (3, 10):
-    def zip(*, strict: bool = ...) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[nothing], *, strict: bool = ...) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[_T], *, strict: bool = ...) -> Iterator[Tuple[_T]]: ...
-    def zip(seq1: Iterable[nothing], seq2: Iterable, *, strict: bool = ...) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable, seq2: Iterable[nothing], *, strict: bool = ...) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[_T], seq2: Iterable[_T2], *, strict: bool = ...) -> Iterator[Tuple[_T, _T2]]: ...
-    def zip(seq1, seq2, seq3, *seqs: Iterable, strict: bool = ...) -> Iterator[tuple]: ...
+    class zip(Iterable[_S]):
+        @overload
+        def __new__(cls, *, strict: bool = ...) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq: Iterable[nothing], *, strict: bool = ...) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq: Iterable[_T], *, strict: bool = ...) -> zip[Tuple[_T]]: ...
+        @overload
+        def __new__(cls, seq1: Iterable[nothing], seq2: Iterable, *, strict: bool = ...) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq1: Iterable, seq2: Iterable[nothing], *, strict: bool = ...) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq1: Iterable[_T], seq2: Iterable[_T2], *, strict: bool = ...) -> zip[Tuple[_T, _T2]]: ...
+        @overload
+        def __new__(cls, seq1, seq2, seq3, *seqs: Iterable, strict: bool = ...) -> zip[tuple]: ...
 else:
-    def zip() -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[nothing]) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[_T]) -> Iterator[Tuple[_T]]: ...
-    def zip(seq1: Iterable[nothing], seq2: Iterable) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable, seq2: Iterable[nothing]) -> Iterator[nothing]: ...
-    def zip(seq1: Iterable[_T], seq2: Iterable[_T2]) -> Iterator[Tuple[_T, _T2]]: ...
-    def zip(seq1, seq2, seq3, *seqs: Iterable) -> Iterator[tuple]: ...
+    class zip(Iterable[_S]):
+        @overload
+        def __new__(cls) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq: Iterable[nothing]) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq: Iterable[_T]) -> zip[Tuple[_T]]: ...
+        @overload
+        def __new__(cls, seq1: Iterable[nothing], seq2: Iterable) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq1: Iterable, seq2: Iterable[nothing]) -> zip[nothing]: ...
+        @overload
+        def __new__(cls, seq1: Iterable[_T], seq2: Iterable[_T2]) -> zip[Tuple[_T, _T2]]: ...
+        @overload
+        def __new__(cls, seq1, seq2, seq3, *seqs: Iterable) -> zip[tuple]: ...
 
 # Keyword constants cannot be assigned here; they are defined in the parser.
 # False: bool = ...

pytype/test_data/complex.pyi

@@ -1,7 +1,7 @@
-from typing import Any, Iterator
+from typing import Any
 
 v = ...  # type: list
 w = ...  # type: list
 x = ...  # type: list
 y = ...  # type: list
-z = ...  # type: Iterator[tuple]
+z = ...  # type: zip[tuple]

pytype/tests/test_builtins4.py

@@ -451,11 +451,11 @@ def test_zip(self):
     """)
     self.assertTypesMatchPytd(ty, """
       from typing import Iterator, Tuple, Union
-      a : Iterator[nothing]
-      b : Iterator[Tuple[Union[int, complex]]]
-      c : Iterator[nothing]
-      d : Iterator[nothing]
-      e : Iterator[Tuple[complex, int]]
+      a: zip[nothing]
+      b: zip[Tuple[Union[int, complex]]]
+      c: zip[nothing]
+      d: zip[nothing]
+      e: zip[Tuple[complex, int]]
       """)
 
   def test_dict(self):
@@ -615,7 +615,7 @@ def test_iterator_builtins(self):
     self.assertTypesMatchPytd(ty, """
       from typing import Iterator, Tuple
       v1 : Iterator[int]
-      v2 : Iterator[Tuple[int, int]]
+      v2 : zip[Tuple[int, int]]
     """)
 
   def test_next(self):