use f-strings instead of +

Author: cadenmyers13

src/diffpy/labpdfproc/labpdfprocapp.py

@@ -131,14 +131,14 @@ def _add_credit_args(parser, use_gui=False):
 
 
 def _save_corrected(corrected, input_path, args):
-    outfile = args.output_directory / (input_path.stem + "-mud-corrected.chi")
+    outfile = args.output_directory / (f"{input_path.stem}-mud-corrected.chi")
     corrected.metadata = corrected.metadata or {}
     corrected.dump(str(outfile), xtype=args.xtype)
     print(f"Saved corrected data to {outfile}")
 
 
 def _save_correction(correction, input_path, args):
-    corrfile = args.output_directory / (input_path.stem + "-cve.chi")
+    corrfile = args.output_directory / (f"{input_path.stem}-cve.chi")
     correction.metadata = correction.metadata or {}
     correction.dump(str(corrfile), xtype=args.xtype)
     print(f"Saved correction data to {corrfile}")

src/diffpy/labpdfproc/tools.py

@@ -533,11 +533,11 @@ def _check_saved_file_exists(args):
     and output directory."""
     existing_files = []
     for path in args.input_paths:
-        outfile = args.output_directory / (path.stem + "-mud-corrected.chi")
+        outfile = args.output_directory / (f"{path.stem}-mud-corrected.chi")
         if outfile.exists() and not args.force:
             existing_files.append(outfile)
         if args.output_correction:
-            corrfile = args.output_directory / (path.stem + "-cve.chi")
+            corrfile = args.output_directory / (f"{path.stem}-cve.chi")
             if corrfile.exists() and not args.force:
                 existing_files.append(corrfile)
     if existing_files: