Use driver code for the main method of a script

Author: CodeByAidan

leetcode.py

@@ -217,6 +217,7 @@ def set_show_status(self) -> None:
         self.set_by_index()
 
 
-root = Tk()
-Leetcode(root)
-root.mainloop()
+if __name__ == "__main__":
+    root = Tk()
+    Leetcode(root)
+    root.mainloop()