From b70f517d539fef4bef6ff5f7af1f22589063ff7f Mon Sep 17 00:00:00 2001
From: Ziwen Liu <ziwen.liu@czbiohub.org>
Date: Wed, 9 Aug 2023 12:29:52 -0700
Subject: [PATCH 1/3] fix slicing when trainer is None

---
 viscy/light/data.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/viscy/light/data.py b/viscy/light/data.py
index b95d41c1..fcab063c 100644
--- a/viscy/light/data.py
+++ b/viscy/light/data.py
@@ -433,7 +433,11 @@ def _setup_predict(self, dataset_settings: dict):
         )
 
     def on_before_batch_transfer(self, batch: Sample, dataloader_idx: int) -> Sample:
-        if self.trainer.predicting or isinstance(batch, torch.Tensor):
+        predicting= False
+        if self.trainer:
+            if self.trainer.predicting:
+                predicting = True
+        if predicting or isinstance(batch, torch.Tensor):
             # skipping example input array
             return batch
         if self.target_2d:

From 8fcc41b1054233bf98baad3b37ba7c533bfb9a96 Mon Sep 17 00:00:00 2001
From: Ziwen Liu <ziwen.liu@czbiohub.org>
Date: Wed, 9 Aug 2023 12:33:40 -0700
Subject: [PATCH 2/3] do not persist workers number is 0

---
 viscy/light/data.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/viscy/light/data.py b/viscy/light/data.py
index fcab063c..06d8fd38 100644
--- a/viscy/light/data.py
+++ b/viscy/light/data.py
@@ -452,7 +452,7 @@ def train_dataloader(self):
             batch_size=self.batch_size,
             num_workers=self.num_workers,
             shuffle=True,
-            persistent_workers=True,
+            persistent_workers=bool(self.num_workers),
         )
 
     def val_dataloader(self):
@@ -461,7 +461,7 @@ def val_dataloader(self):
             batch_size=self.batch_size,
             num_workers=self.num_workers,
             shuffle=False,
-            persistent_workers=True,
+            persistent_workers=bool(self.num_workers),
         )
 
     def test_dataloader(self):

From 6edebc20e02eccd2a58a1c4759efb516d2ce27ab Mon Sep 17 00:00:00 2001
From: Ziwen Liu <ziwen.liu@czbiohub.org>
Date: Wed, 9 Aug 2023 12:34:25 -0700
Subject: [PATCH 3/3] style

---
 viscy/light/data.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/viscy/light/data.py b/viscy/light/data.py
index 06d8fd38..9e0d60f2 100644
--- a/viscy/light/data.py
+++ b/viscy/light/data.py
@@ -433,7 +433,7 @@ def _setup_predict(self, dataset_settings: dict):
         )
 
     def on_before_batch_transfer(self, batch: Sample, dataloader_idx: int) -> Sample:
-        predicting= False
+        predicting = False
         if self.trainer:
             if self.trainer.predicting:
                 predicting = True