fix len error (#1981)

Co-authored-by: eellison <eellison@fb.com>

torchvision/ops/misc.py

@@ -77,12 +77,13 @@ def _check_size_scale_factor(dim, size, scale_factor):
         raise ValueError("either size or scale_factor should be defined")
     if size is not None and scale_factor is not None:
         raise ValueError("only one of size or scale_factor should be defined")
-    if scale_factor is not None and isinstance(scale_factor, tuple)\
-            and len(scale_factor) != dim:
-        raise ValueError(
-            "scale_factor shape must match input shape. "
-            "Input is {}D, scale_factor size is {}".format(dim, len(scale_factor))
-        )
+    if scale_factor is not None: 
+        if isinstance(scale_factor, (list, tuple)):
+            if len(scale_factor) != dim:
+                raise ValueError(
+                    "scale_factor shape must match input shape. "
+                    "Input is {}D, scale_factor size is {}".format(dim, len(scale_factor))
+                )
 
 
 def _output_size(dim, input, size, scale_factor):