Don't create lists only to access the first item

RUF015: 'Prefer `next(iter(...))` over single element slice'

Author: NMertsch

src/briefcase/commands/dev.py

@@ -230,7 +230,7 @@ def __call__(
         # in pyproject.toml, then we can use it as a default;
         # otherwise look for a -a/--app option.
         if len(self.apps) == 1:
-            app = list(self.apps.values())[0]
+            app = next(iter(self.apps.values()))
         elif appname:
             try:
                 app = self.apps[appname]

src/briefcase/commands/run.py

@@ -278,7 +278,7 @@ def __call__(
         # in pyproject.toml, then we can use it as a default;
         # otherwise look for a -a/--app option.
         if len(self.apps) == 1:
-            app = list(self.apps.values())[0]
+            app = next(iter(self.apps.values()))
         elif appname:
             try:
                 app = self.apps[appname]

src/briefcase/platforms/iOS/xcode.py

@@ -213,7 +213,7 @@ def select_target_device(self, udid_or_device=None):
         if len(simulators) == 0:
             raise BriefcaseCommandError("No iOS simulators available.")
         elif len(simulators) == 1:
-            iOS_tag = list(simulators.keys())[0]
+            iOS_tag = next(iter(simulators.keys()))
         else:
             iOS_tag = self.console.selection_question(
                 intro="Select iOS version:",
@@ -226,7 +226,7 @@ def select_target_device(self, udid_or_device=None):
         if len(devices) == 0:
             raise BriefcaseCommandError(f"No simulators available for {iOS_tag}.")
         elif len(devices) == 1:
-            udid = list(devices.keys())[0]
+            udid = next(iter(devices.keys()))
         else:
             udid = self.console.selection_question(
                 intro="Select simulator device to use:",