Modernize code with Python 3.10+ idioms

- Replace .format() with f-string in _tracing.py
- Use walrus operator for dict.get() pattern in _tracing.py
- Convert string concatenation to parenthesized f-strings in _callers.py

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: RonnyPfannschmidt

src/pluggy/_callers.py

@@ -66,10 +66,12 @@ def _raise_wrapfail(
 def _warn_teardown_exception(
     hook_name: str, hook_impl: HookImpl, e: BaseException
 ) -> None:
-    msg = "A plugin raised an exception during an old-style hookwrapper teardown.\n"
-    msg += f"Plugin: {hook_impl.plugin_name}, Hook: {hook_name}\n"
-    msg += f"{type(e).__name__}: {e}\n"
-    msg += "For more information see https://pluggy.readthedocs.io/en/stable/api_reference.html#pluggy.PluggyTeardownRaisedWarning"  # noqa: E501
+    msg = (
+        f"A plugin raised an exception during an old-style hookwrapper teardown.\n"
+        f"Plugin: {hook_impl.plugin_name}, Hook: {hook_name}\n"
+        f"{type(e).__name__}: {e}\n"
+        f"For more information see https://pluggy.readthedocs.io/en/stable/api_reference.html#pluggy.PluggyTeardownRaisedWarning"  # noqa: E501
+    )
     warnings.warn(PluggyTeardownRaisedWarning(msg), stacklevel=6)
 
 

src/pluggy/_tracing.py

@@ -32,7 +32,7 @@ def _format_message(self, tags: Sequence[str], args: Sequence[object]) -> str:
         content = " ".join(map(str, args))
         indent = "  " * self.indent
 
-        lines = ["{}{} [{}]\n".format(indent, content, ":".join(tags))]
+        lines = [f"{indent}{content} [{':'.join(tags)}]\n"]
 
         for name, value in extra.items():
             lines.append(f"{indent}    {name}: {value}\n")
@@ -42,11 +42,7 @@ def _format_message(self, tags: Sequence[str], args: Sequence[object]) -> str:
     def _processmessage(self, tags: tuple[str, ...], args: tuple[object, ...]) -> None:
         if self._writer is not None and args:
             self._writer(self._format_message(tags, args))
-        try:
-            processor = self._tags2proc[tags]
-        except KeyError:
-            pass
-        else:
+        if processor := self._tags2proc.get(tags):
             processor(tags, args)
 
     def setwriter(self, writer: _Writer | None) -> None: