Optimize JSON serialization, template reuse, and module introspection

src/cookiecutter_python/backend/helpers.py

@@ -65,15 +65,15 @@ def parse_context(config_file: str):
         user_default_context = {}
         user_interpreters = cook_json['interpreters']
 
-    context_defaults = dict(
-        cook_json,
-        **{k: v for k, v in user_default_context.items()},
-        **{k: v[0] for k, v in choices.items() if k not in user_default_context},
-    )
+    # Optimize: Build context_defaults in a single pass
+    context_defaults = dict(cook_json, **user_default_context)
+    for k, v in choices.items():
+        if k not in context_defaults:
+            context_defaults[k] = v[0]
 
     # Render cookiecutter.json again with context to resolve derived fields
     # This ensures derived fields like pkg_name get computed properly
-    template = env.get_template('cookiecutter.json')
+    # Optimize: Reuse template object instead of getting it again
     rendered_with_context = template.render({'cookiecutter': context_defaults})
     resolved_cook_json: t.Mapping[str, t.Any] = json.loads(rendered_with_context)
 

src/cookiecutter_python/backend/hosting_services/extract_name.py

@@ -31,20 +31,16 @@ def __call__(self, config_file: str) -> str:
         try:
             return self.name_extractor(context_data)
         except KeyError as error:
+            # Optimize: Sort before converting to string, remove unnecessary indent and sort_keys
+            available_vars = ', '.join(str(x) for x in sorted(context_data.keys()))
             raise ContextVariableDoesNotExist(
                 "{msg}: {data}".format(
-                    msg="Attempted to retrieve non-existant variable",
+                    msg="Attempted to retrieve non-existent variable",
                     data=json.dumps(
                         {
                             'variable_name': str(self.name_extractor),
-                            'available_variables': '[{keys}]'.format(
-                                keys=', '.join(
-                                    tuple(sorted([str(x) for x in context_data.keys()]))
-                                ),
-                            ),
+                            'available_variables': f'[{available_vars}]',
                         },
-                        indent=4,
-                        sort_keys=True,
                     ),
                 ),
             ) from error

src/cookiecutter_python/backend/proxy.py

@@ -18,6 +18,4 @@ def log_info_args(message: str, *args, **kwargs) -> Tuple[str, str]:
                 'keyword_args': {k: str(v) for k, v in kwargs.items()},
                 'positional_args': [str(arg_value) for arg_value in args],
             },
-            indent=4,
-            sort_keys=True,
         )

src/cookiecutter_python/utils.py

@@ -49,9 +49,9 @@ def load(interface: t.Type[T], module: t.Optional[str] = None) -> t.List[t.Type[
             '{package}.{module}'.format(package=dotted_lib_path, module=module_name)
         )
 
-        for attribute_name in dir(module_object):
-            attribute = getattr(module_object, attribute_name)
-
+        # Optimize: Use vars() instead of dir() + getattr() for better performance
+        # Note: For module objects, vars() returns the same attributes as dir() (excluding builtins)
+        for attribute_name, attribute in vars(module_object).items():
             if (
                 attribute != interface
                 and isclass(attribute)