Add string.templatelib in 3.14 (#14044)

stdlib/string/templatelib.pyi

@@ -0,0 +1,28 @@
+from collections.abc import Iterator
+from typing import Any, Literal, final
+
+__all__ = ["Interpolation", "Template"]
+
+@final
+class Template:  # TODO: consider making `Template` generic on `TypeVarTuple`
+    strings: tuple[str, ...]
+    interpolations: tuple[Interpolation, ...]
+
+    def __new__(cls, *args: str | Interpolation) -> Template: ...
+    def __iter__(self) -> Iterator[str | Interpolation]: ...
+    def __add__(self, other: Template | str) -> Template: ...
+    @property
+    def values(self) -> tuple[Any, ...]: ...  # Tuple of interpolation values, which can have any type
+
+@final
+class Interpolation:
+    value: Any  # TODO: consider making `Interpolation` generic in runtime
+    expression: str
+    conversion: Literal["a", "r", "s"] | None
+    format_spec: str
+
+    __match_args__ = ("value", "expression", "conversion", "format_spec")
+
+    def __new__(
+        cls, value: Any, expression: str, conversion: Literal["a", "r", "s"] | None = None, format_spec: str = ""
+    ) -> Interpolation: ...