scripts: use str.format() instead of concatenating in some places

SpriteEncoder/decode.py

@@ -158,7 +158,7 @@ class Sprite:
                         y = y + 1
                 continue
 
-        im.save("sprite_" + str(self.number) + ".png")
+        im.save("sprite_{}.png".format(self.number))
 
 
 inf = Infile("x.out")

scripts/check_language_files_not_BOM.py

@@ -21,7 +21,7 @@ def is_BOM_encoded_file(path):
 
 
 if len(sys.argv) > 2:
-  sys.exit('Usage: ' + sys.argv[0] + ' [root]')
+  sys.exit('Usage: {} [root]'.format(sys.argv[0]))
 
 top = os.getcwd()
 if len(sys.argv) == 2:

scripts/check_lua_classes.py

@@ -24,7 +24,7 @@ for root, _, files in os.walk(script_dir):
           problem_found = True
           print("Invalid/Improper Class Declarations Found:")
         path = print_root_regex.search(root).group(0)
-        print("*" + path + "\\" + script + ":" + found_class)
+        print("*{}:{}".format(os.path.join(path, script), found_class))
 
 if problem_found:
   print("\nReason: The class declaration(s) didn't begin as follows:")

scripts/check_trailing_whitespaces.py

@@ -28,7 +28,7 @@ def has_trailing_whitespaces(path):
 
 
 if len(sys.argv) > 2:
-  sys.exit('Usage: ' + sys.argv[0] + ' [root]')
+  sys.exit('Usage: {} [root]'.format(sys.argv[0]))
 
 top = os.getcwd()
 if len(sys.argv) == 2: