From 67e29d2548839ecc6ab91802f746c5fba704ffc2 Mon Sep 17 00:00:00 2001
From: Ran Benita <ran@unusedvar.com>
Date: Mon, 15 Aug 2022 19:12:12 +0300
Subject: [PATCH] mark: allow any Sequence[str] for parametrize(argnames), not
 just list/tuple

The main motivation for this change is to simplify the type shown in
code editors -- `Sequence[str]` is easier to follow than
`Union[list[str], tuple[str, ...]]`.

It also permits using other types if desired. It might lead to problems
if someone uses some oddball sequence type, but hopefully they won't do
that.
---
 changelog/10218.improvement.rst |  5 +++++
 src/_pytest/mark/structures.py  | 12 ++++++------
 src/_pytest/python.py           |  2 +-
 3 files changed, 12 insertions(+), 7 deletions(-)
 create mode 100644 changelog/10218.improvement.rst

diff --git a/changelog/10218.improvement.rst b/changelog/10218.improvement.rst
new file mode 100644
index 000000000..e00325e25
--- /dev/null
+++ b/changelog/10218.improvement.rst
@@ -0,0 +1,5 @@
+``@pytest.mark.parametrize()`` (and similar functions) now accepts any ``Sequence[str]`` for the argument names,
+instead of just ``list[str]`` and ``tuple[str, ...]``.
+
+(Note that ``str``, which is itself a ``Sequence[str]``, is still treated as a
+comma-delimited name list, as before).
diff --git a/src/_pytest/mark/structures.py b/src/_pytest/mark/structures.py
index b8cbf0d18..800a25c92 100644
--- a/src/_pytest/mark/structures.py
+++ b/src/_pytest/mark/structures.py
@@ -126,12 +126,12 @@ class ParameterSet(NamedTuple):
 
     @staticmethod
     def _parse_parametrize_args(
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union["ParameterSet", Sequence[object], object]],
         *args,
         **kwargs,
-    ) -> Tuple[Union[List[str], Tuple[str, ...]], bool]:
-        if not isinstance(argnames, (tuple, list)):
+    ) -> Tuple[Sequence[str], bool]:
+        if isinstance(argnames, str):
             argnames = [x.strip() for x in argnames.split(",") if x.strip()]
             force_tuple = len(argnames) == 1
         else:
@@ -150,12 +150,12 @@ class ParameterSet(NamedTuple):
     @classmethod
     def _for_parametrize(
         cls,
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union["ParameterSet", Sequence[object], object]],
         func,
         config: Config,
         nodeid: str,
-    ) -> Tuple[Union[List[str], Tuple[str, ...]], List["ParameterSet"]]:
+    ) -> Tuple[Sequence[str], List["ParameterSet"]]:
         argnames, force_tuple = cls._parse_parametrize_args(argnames, argvalues)
         parameters = cls._parse_parametrize_parameters(argvalues, force_tuple)
         del argvalues
@@ -434,7 +434,7 @@ if TYPE_CHECKING:
     class _ParametrizeMarkDecorator(MarkDecorator):
         def __call__(  # type: ignore[override]
             self,
-            argnames: Union[str, List[str], Tuple[str, ...]],
+            argnames: Union[str, Sequence[str]],
             argvalues: Iterable[Union[ParameterSet, Sequence[object], object]],
             *,
             indirect: Union[bool, Sequence[str]] = ...,
diff --git a/src/_pytest/python.py b/src/_pytest/python.py
index 91054f370..3db877506 100644
--- a/src/_pytest/python.py
+++ b/src/_pytest/python.py
@@ -1207,7 +1207,7 @@ class Metafunc:
 
     def parametrize(
         self,
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union[ParameterSet, Sequence[object], object]],
         indirect: Union[bool, Sequence[str]] = False,
         ids: Optional[