Requested changes and formatting

SConstruct

@@ -8,6 +8,7 @@ from binding_generator import scons_generate_bindings, scons_emit_files
 
 EnsureSConsVersion(4, 0)
 
+
 def add_sources(sources, dir, extension):
     for f in os.listdir(dir):
         if f.endswith("." + extension):
@@ -59,9 +60,6 @@ opts.Add(
     )
 )
 
-opts.Add(BoolVariable("cache", "Cache results for faster iteration when develloping.", False))
-opts.Add(PathVariable("cache_dir", "Where you want your cache directory.", "cache", PathVariable.PathIsDirCreate))
-
 # Must be the same setting as used for cpp_bindings
 opts.Add(EnumVariable("target", "Compilation target", "debug", allowed_values=("debug", "release"), ignorecase=2))
 opts.Add(
@@ -170,12 +168,14 @@ else:
     json_api_file = os.path.join(os.getcwd(), env["headers_dir"], "extension_api.json")
 
 bindings = env.GenerateBindings(
-    env.Dir("."), [json_api_file, os.path.join(env["headers_dir"], "godot", "gdnative_interface.h"), "binding_generator.py"]
+    env.Dir("."),
+    [json_api_file, os.path.join(env["headers_dir"], "godot", "gdnative_interface.h"), "binding_generator.py"]
 )
 
-if(env["cache"]):
-    CacheDir(env["cache_dir"])
-    Decider('MD5')
+scons_cache_path = os.environ.get("SCONS_CACHE")
+if scons_cache_path is not None:
+    CacheDir(scons_cache_path)
+    Decider("MD5")
 
 # Forces bindings regeneration.
 if env["generate_bindings"]:

binding_generator.py

@@ -203,7 +203,7 @@ def generate_builtin_bindings(api, output_dir, build_config):
         for type_name in fully_used_classes:
             if type_name in used_classes:
                 used_classes.remove(type_name)
-                
+
         used_classes = list(used_classes)
         used_classes.sort()
         fully_used_classes = list(fully_used_classes)
@@ -892,7 +892,7 @@ def generate_engine_classes_bindings(api, output_dir, use_template_get_node):
         for type_name in fully_used_classes:
             if type_name in used_classes:
                 used_classes.remove(type_name)
-                
+
         used_classes = list(used_classes)
         used_classes.sort()
         fully_used_classes = list(fully_used_classes)