use os.path.join

Author: ArnoutD

plugwise_usb/helpers/cache.py

@@ -59,10 +59,8 @@ async def initialize_cache(self, create_root_folder: bool = False) -> None:
             cache_dir = self._get_writable_os_dir()
         await makedirs(cache_dir, exist_ok=True)
         self._cache_path = cache_dir
-        if os_name == "nt":
-            self._cache_file = f"{cache_dir}\\{self._file_name}"
-        else:
-            self._cache_file = f"{cache_dir}/{self._file_name}"
+        
+        self._cache_file = os_path_join(self._cache_path, self._file_name)
         self._cache_file_exists = await ospath.exists(self._cache_file)
         self._initialized = True
         _LOGGER.debug("Start using network cache file: %s", self._cache_file)