diff --git a/aiidalab_sssp/inspect/subwidgets/delta.py b/aiidalab_sssp/inspect/subwidgets/delta.py
index 80be406..fb7dc18 100644
--- a/aiidalab_sssp/inspect/subwidgets/delta.py
+++ b/aiidalab_sssp/inspect/subwidgets/delta.py
@@ -1,6 +1,7 @@
 """Moudle contains widgets for accuracy delat results inspect.
 The widget EosComparisonWidget for compare Eos fit line of a given pseudos in the given configuration.
 The widget AccuracyMeritWidget showing Nicola's Nu measure of all pseudos in all configurations"""
+
 import ipywidgets as ipw
 import matplotlib.pyplot as plt
 import numpy as np
diff --git a/aiidalab_sssp/process.py b/aiidalab_sssp/process.py
index 0d1b7b8..1f08bf4 100644
--- a/aiidalab_sssp/process.py
+++ b/aiidalab_sssp/process.py
@@ -1,4 +1,5 @@
 """Widgets related to process management."""
+
 from dataclasses import dataclass
 from threading import Event, Lock, Thread
 
diff --git a/aiidalab_sssp/steps.py b/aiidalab_sssp/steps.py
index 7fb60a3..484ad3b 100644
--- a/aiidalab_sssp/steps.py
+++ b/aiidalab_sssp/steps.py
@@ -1,4 +1,5 @@
 """widget for pseudo inmport"""
+
 import io
 import os
 
diff --git a/inspect.ipynb b/inspect.ipynb
index f5729f1..89bb628 100644
--- a/inspect.ipynb
+++ b/inspect.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "fe6d78c0",
+   "id": "0",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -17,7 +17,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "fcd02c89",
+   "id": "1",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -27,7 +27,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "ba9715ad",
+   "id": "2",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/setup.cfg b/setup.cfg
index 1dd7a39..9cd76ce 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -8,15 +8,12 @@ url = https://github.com/aiidalab/aiidalab-sssp
 author = Jusong Yu
 author_email = jusong.yu@psi.ch
 license = MIT
-license_file = LICENSE
+license_files = LICENSE
 classifiers =
     License :: OSI Approved :: MIT License
     Operating System :: OS Independent
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
-    Programming Language :: Python :: 3.10
 project_urls =
     Logo = https://raw.githubusercontent.com/aiidalab/aiidalab-sssp/main/miscellaneous/logo-sssp.png
     Bug Tracker = https://github.com/aiidalab/aiidalab-sssp/issues
diff --git a/sssp-docs.ipynb b/sssp-docs.ipynb
index 85ba71e..4594334 100644
--- a/sssp-docs.ipynb
+++ b/sssp-docs.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "markdown",
-   "id": "dd3be55d",
+   "id": "0",
    "metadata": {},
    "source": [
     "## $\\Delta$ measures (normol $\\Delta$-factor and $\\nu\\Delta$ the 'length of the vector' measure)\n",
@@ -43,7 +43,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "800d43b8",
+   "id": "1",
    "metadata": {},
    "source": [
     "## Cohesive energy (eV/atom)\n",
@@ -66,7 +66,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "475abb76",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Cohesive energy error (eV/atom)\n",
@@ -83,7 +83,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a81a9a26",
+   "id": "3",
    "metadata": {},
    "source": [
     "## Phonon frequencies absolute error ($cm^{-1}$)\n",
@@ -101,7 +101,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44922944",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Phonon frequencies relative error (%)\n",
@@ -120,7 +120,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "62b8337f",
+   "id": "5",
    "metadata": {},
    "source": [
     "## Pressure absolute error (GPa)\n",
@@ -134,7 +134,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1a874e26",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Pressure relative error (GPa)\n",
diff --git a/viewers.py b/viewers.py
index f4aaefd..667fbc8 100644
--- a/viewers.py
+++ b/viewers.py
@@ -26,7 +26,7 @@ def viewer(obj, downloadable=True, **kwargs):
     try:
         _viewer = AIIDA_VIEWER_MAPPING[obj.node_type]
         return _viewer(obj, downloadable=downloadable, **kwargs)
-    except (KeyError) as exc:
+    except KeyError as exc:
         if obj.node_type in str(exc):
             warnings.warn(
                 "Did not find an appropriate viewer for the {} object. Returning the object "