examples/chroottar.py: improve typing precision

1 files changed, 5 insertions, 1 deletions

diff --git a/examples/chroottar.py b/examples/chroottar.py
index 523892c..8b374d1 100755
--- a/examples/chroottar.py
+++ b/examples/chroottar.py
@@ -13,6 +13,7 @@ import socket
 import sys
 import tarfile
 import tempfile
+import typing
 
 if __file__.split("/")[-2:-1] == ["examples"]:
     sys.path.insert(0, "/".join(__file__.split("/")[:-2]))
@@ -27,7 +28,10 @@ class TarFile(tarfile.TarFile):
 
     @classmethod
     def zstopen(
-        cls, name: str, mode: str = "r", fileobj: None = None
+        cls,
+        name: str,
+        mode: typing.Literal["r", "w", "x"] = "r",
+        fileobj: None = None,
     ) -> tarfile.TarFile:
         if mode not in ("r", "w", "x"):
             raise NotImplementedError(f"mode `{mode}' not implemented for zst")