diff --git a/main.py b/main.py
index 21e81352..413e5e29 100644
--- a/main.py
+++ b/main.py
@@ -1,4 +1,4 @@
-import argparse, os, sys, datetime, glob, importlib, csv
+import argparse, os, sys, datetime, glob
 import numpy as np
 import time
 import torch
@@ -7,13 +7,13 @@
 
 from packaging import version
 from omegaconf import OmegaConf
-from torch.utils.data import random_split, DataLoader, Dataset, Subset
+from torch.utils.data import DataLoader, Dataset
 from functools import partial
 from PIL import Image
 
 from pytorch_lightning import seed_everything
 from pytorch_lightning.trainer import Trainer
-from pytorch_lightning.callbacks import ModelCheckpoint, Callback, LearningRateMonitor
+from pytorch_lightning.callbacks import Callback
 from pytorch_lightning.utilities.distributed import rank_zero_only
 from pytorch_lightning.utilities import rank_zero_info
 
diff --git a/scripts/checker.py b/scripts/checker.py
index 8b94a5ba..884096ef 100644
--- a/scripts/checker.py
+++ b/scripts/checker.py
@@ -1,6 +1,5 @@
 import os
 import glob
-import subprocess
 import time
 import fire
 
diff --git a/scripts/img2img.py b/scripts/img2img.py
index 413b0e46..e81779ff 100644
--- a/scripts/img2img.py
+++ b/scripts/img2img.py
@@ -1,6 +1,6 @@
 """make variations of input image"""
 
-import argparse, os, sys, glob
+import argparse, os
 import PIL
 import torch
 import numpy as np
diff --git a/scripts/inpaint.py b/scripts/inpaint.py
index d6e6387a..ad280e45 100644
--- a/scripts/inpaint.py
+++ b/scripts/inpaint.py
@@ -1,4 +1,4 @@
-import argparse, os, sys, glob
+import argparse, os, glob
 from omegaconf import OmegaConf
 from PIL import Image
 from tqdm import tqdm
diff --git a/scripts/inpaint_sd.py b/scripts/inpaint_sd.py
index 568a0bc5..72af7a3f 100644
--- a/scripts/inpaint_sd.py
+++ b/scripts/inpaint_sd.py
@@ -1,4 +1,4 @@
-import argparse, os, sys, glob
+import argparse, os, glob
 from omegaconf import OmegaConf
 from PIL import Image
 from tqdm import tqdm
diff --git a/scripts/logging_template.py b/scripts/logging_template.py
index 2199e48d..67675048 100644
--- a/scripts/logging_template.py
+++ b/scripts/logging_template.py
@@ -3,14 +3,8 @@
 import numpy as np
 from omegaconf import OmegaConf
 import streamlit as st
-from streamlit import caching
-from PIL import Image
-from torch.utils.data import DataLoader
 from torch.utils.data.dataloader import default_collate
-import pytorch_lightning as pl
 from pytorch_lightning import seed_everything
-from pytorch_lightning.callbacks import Callback
-from pytorch_lightning.utilities.distributed import rank_zero_only
 from tqdm import tqdm
 import datetime
 
diff --git a/scripts/mnist-distributed.py b/scripts/mnist-distributed.py
index 2a28f78a..b3f72aaf 100644
--- a/scripts/mnist-distributed.py
+++ b/scripts/mnist-distributed.py
@@ -7,7 +7,6 @@
 import torch
 import torch.nn as nn
 import torch.distributed as dist
-from apex.parallel import DistributedDataParallel as DDP
 from apex import amp
 
 
diff --git a/scripts/test_gpu.py b/scripts/test_gpu.py
index 36d4e781..1570911e 100644
--- a/scripts/test_gpu.py
+++ b/scripts/test_gpu.py
@@ -1,5 +1,7 @@
 import socket
-try:
+
+
+def main() -> int:
     import torch
     n_gpus = torch.cuda.device_count()
     print(f"checking {n_gpus} gpus.")
@@ -16,7 +18,10 @@
         out = net(data)
         out.backward(torch.randn_like(out))
         torch.cuda.synchronize()
-except RuntimeError as err:
+    return 1
+
+
+def runtime_error_case() -> None:
     import requests
     import datetime
     import os
@@ -26,5 +31,12 @@
     resp = requests.get('http://169.254.169.254/latest/meta-data/instance-id')
     print(f'ERROR at {ts} on {hostname}/{resp.text} (CUDA_VISIBLE_DEVICES={device}): {type(err).__name__}: {err}', flush=True)
     raise err
-else:
-    print(f"checked {socket.gethostname()}")
+
+
+if __name__ == '__main__':
+    try:
+        main()
+    except RuntimeError as err:
+        runtime_error_case()
+    else:
+        print(f"checked {socket.gethostname()}")