chore: minor PEP8 fixes, add -Sy rationale comment

iso-profiles/antergos/live-overlay/usr/lib/calamares/modules/basestrap/main.py

@@ -344,6 +344,7 @@ class PMPacman(PackageManager):
         if from_local:
             command.append("-U")
         else:
+            # -Sy is intentional: fresh chroot has no pacman DB, must sync first
             command.append("-Sy")
             command.append("--overwrite=*")
 
@@ -388,9 +389,9 @@ class PMPacman(PackageManager):
         path = join(rootdir, "run")
         os.chmod(path, 0o755)
 
-    def copy_file(self, rootdir, f):
-        if os.path.exists(join("/",f)):
-            shutil.copy2(join("/",f), join(rootdir, f))
+    def copy_file(self, rootdir, relative_path):
+        if os.path.exists(join("/", relative_path)):
+            shutil.copy2(join("/", relative_path), join(rootdir, relative_path))
 
     def init_keyring(self):
         target_env_process_output(["pacman-key", "--init"])