Replace self.__directory with Path object and raise QueueDoesNotExist…

…Error if queue does not exist

src/webqueue2api/parser/queue.py

@@ -1,6 +1,8 @@
 import os, re
+from pathlib import Path
 from .item import Item
 from .config import config
+from .errors import QueueDoesNotExistError
 
 
 
@@ -18,11 +20,17 @@ class Queue:
             name: The name of the queue.
             items: A list of Items in the queue.
             jsonData: A JSON serializable representation of the Queue.
+
+    Raises:
+            QueueDoesNotExistError: If a queue's directory does not exist on the filesystem.
     """
 
     def __init__(self, name: str) -> None:
         self.name = name
-        self.__directory = config.queue_directory + "/" + self.name + "/"
+        self.__directory = Path(config.queue_directory, self.name)
+        if not self.__directory.exists():
+            raise QueueDoesNotExistError(str(self.__directory))
+
         self.items = self.__getItems()
 
         self.jsonData = {
@@ -39,9 +47,9 @@ def __getItems(self) -> list:
         items = []
 
         for item in os.listdir(self.__directory):
-            itemPath = self.__directory + "/" + item
+            item_path = Path(self.__directory, item)
 
-            isFile = True if os.path.isfile(itemPath) else False
+            isFile = True if os.path.isfile(item_path) else False
 
             if isFile and isValidItemName(item):
                 items.append(Item(self.name, item))