MAINT: review comments

Author: ev-br

torch_np/_funcs_impl.py

@@ -1260,14 +1260,13 @@ def einsum(*operands, out=None, optimize=False, **kwargs):
         raise TypeError("unknown arguments: ", kwargs)
 
     # parse arrays and normalize them
-    if isinstance(operands[0], str):
-        # ("ij->", arrays) format
-        sublist_format = False
-        subscripts, array_operands = operands[0], operands[1:]
-    else:
+    sublist_format = not isinstance(operands[0], str)
+    if sublist_format:
         # op, str, op, str ... format: normalize every other argument
-        sublist_format = True
         array_operands = operands[:-1][::2]
+    else:
+        # ("ij->", arrays) format
+        subscripts, array_operands = operands[0], operands[1:]
 
     tensors = [normalize_array_like(op) for op in array_operands]
     target_dtype = (
@@ -1291,8 +1290,6 @@ def einsum(*operands, out=None, optimize=False, **kwargs):
     else:
         result = torch.einsum(subscripts, *tensors)
 
-
-
     result = maybe_copy_to(out, result)
     return wrap_tensors(result)