Don't call max() in every iteration

bin/calculate_mirror_size.py

@@ -69,11 +69,12 @@ if __name__ == "__main__":
         )
         with TemporaryDirectory() as tmp_dir:
             dir_sizes = []
+            max_dir_len = len(max(mirror_dirs, key=len))
             for dir in mirror_dirs:
                 rsync_cmd = f"rsync -a -n --stats {args['-R']}/{dir}/ | grep '^Total file size' | tr -d ','"
                 output = subprocess.run(rsync_cmd, shell=True, capture_output=True)
                 logstr = (
-                    dir.rjust(len(max(mirror_dirs, key=len)))
+                    dir.rjust(max_dir_len)
                     + " "
                     + human_bytes(int(output.stdout.split()[3]))
                 )