Fix MultiEpochsDataLoader when there's no batching

timm/data/loader.py

@@ -230,12 +230,15 @@ class MultiEpochsDataLoader(torch.utils.data.DataLoader):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self._DataLoader__initialized = False
-        self.batch_sampler = _RepeatSampler(self.batch_sampler)
+        if self.batch_sampler is None:
+            self.sampler = RepeatSampler(self.sampler)
+        else:
+            self.batch_sampler = RepeatSampler(self.batch_sampler)
         self._DataLoader__initialized = True
         self.iterator = super().__iter__()
 
     def __len__(self):
-        return len(self.batch_sampler.sampler)
+        return len(self.sampler) if self.batch_sampler is None else len(self.batch_sampler.sampler)
 
     def __iter__(self):
         for i in range(len(self)):