Refactor to avord redefining argument

src/python/grpcio_tests/tests/_loader.py

@@ -48,12 +48,12 @@ class Loader(object):
         # measure unnecessarily suffers)
         coverage_context = coverage.Coverage(data_suffix=True)
         coverage_context.start()
-        modules = [importlib.import_module(name) for name in names]
-        for module in modules:
-            self.visit_module(module)
-        for module in modules:
+        imported_modules = tuple(importlib.import_module(name) for name in names)
+        for imported_module in imported_modules:
+            self.visit_module(imported_module)
+        for imported_module in imported_modules:
             try:
-                package_paths = module.__path__
+                package_paths = imported_module.__path__
             except AttributeError:
                 continue
             self.walk_packages(package_paths)