diff --git a/.notebook/espnet_dataloader.ipynb b/.notebook/espnet_dataloader.ipynb
index 12870a8ebb75137a52358bc6a73806d563f1cdf2..7abb138ffc97db96ba5e7ff5af2754d19ba97d2c 100644
--- a/.notebook/espnet_dataloader.ipynb
+++ b/.notebook/espnet_dataloader.ipynb
@@ -1058,7 +1058,7 @@
   {
    "cell_type": "code",
    "execution_count": 34,
-   "id": "7f0307eb",
+   "id": "502d3f4d",
    "metadata": {},
    "outputs": [
     {
@@ -1186,7 +1186,7 @@
   {
    "cell_type": "code",
    "execution_count": 84,
-   "id": "1b6508fc",
+   "id": "0b92ade5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1196,7 +1196,7 @@
   {
    "cell_type": "code",
    "execution_count": 85,
-   "id": "25d655c0",
+   "id": "8dbd847c",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1206,7 +1206,7 @@
   {
    "cell_type": "code",
    "execution_count": 87,
-   "id": "a28e5141",
+   "id": "31c085f4",
    "metadata": {},
    "outputs": [
     {
@@ -1300,10 +1300,44 @@
     "print(olen.dtype)"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 88,
+   "id": "72e9ba60",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from pathlib import Path"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 90,
+   "id": "64593e5f",
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "AttributeError",
+     "evalue": "'str' object has no attribute 'stat'",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mAttributeError\u001b[0m                            Traceback (most recent call last)",
+      "\u001b[0;32m/tmp/ipykernel_48616/3505477735.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0ms\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;34m'xxxxxxxx'\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 2\u001b[0;31m \u001b[0mPath\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mis_file\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0ms\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/usr/local/lib/python3.7/pathlib.py\u001b[0m in \u001b[0;36mis_file\u001b[0;34m(self)\u001b[0m\n\u001b[1;32m   1342\u001b[0m         \"\"\"\n\u001b[1;32m   1343\u001b[0m         \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1344\u001b[0;31m             \u001b[0;32mreturn\u001b[0m \u001b[0mS_ISREG\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mstat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mst_mode\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   1345\u001b[0m         \u001b[0;32mexcept\u001b[0m \u001b[0mOSError\u001b[0m \u001b[0;32mas\u001b[0m \u001b[0me\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1346\u001b[0m             \u001b[0;32mif\u001b[0m \u001b[0me\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0merrno\u001b[0m \u001b[0;32mnot\u001b[0m \u001b[0;32min\u001b[0m \u001b[0;34m(\u001b[0m\u001b[0mENOENT\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mENOTDIR\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mAttributeError\u001b[0m: 'str' object has no attribute 'stat'"
+     ]
+    }
+   ],
+   "source": [
+    "s='xxxxxxxx'\n",
+    "Path.is_file(s)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "1d981df4",
+   "id": "fcea3fd0",
    "metadata": {},
    "outputs": [],
    "source": []