All tests passing

opt_einsum/backends/object_arrays.py

@@ -7,8 +7,10 @@
 
 import numpy as np
 
+from opt_einsum.typing import ArrayType
 
-def object_einsum(eq, *arrays):
+
+def object_einsum(eq: str, *arrays: ArrayType) -> ArrayType:
     """A ``einsum`` implementation for ``numpy`` arrays with object dtype.
     The loop is performed in python, meaning the objects themselves need
     only to implement ``__mul__`` and ``__add__`` for the contraction to be

opt_einsum/backends/torch.py

@@ -41,7 +41,7 @@ def transpose(a, axes):
     return a.permute(*axes)
 
 
-def einsum(equation, *operands):
+def einsum(equation, *operands, **kwargs):
     """Variadic version of torch.einsum to match numpy api."""
     # rename symbols to support PyTorch 0.4.1 and earlier,
     # which allow only symbols a-z.

opt_einsum/contract.py

@@ -123,6 +123,26 @@ def _choose_memory_arg(memory_limit: _MemoryLimit, size_list: List[int]) -> Opti
     return int(memory_limit)
 
 
+def _filter_einsum_defaults(kwargs: Dict[Literal["order", "casting", "dtype", "out"], Any]) -> Dict[str, Any]:
+    """Filters out default contract kwargs to pass to various backends."""
+    kwargs = kwargs.copy()
+    ret = {}
+    if (order := kwargs.pop("order", "K")) != "K":
+        ret["order"] = order
+
+    if (casting := kwargs.pop("casting", "safe")) != "safe":
+        ret["casting"] = casting
+
+    if (dtype := kwargs.pop("dtype", None)) is not None:
+        ret["dtype"] = dtype
+
+    if (out := kwargs.pop("out", None)) is not None:
+        ret["out"] = out
+
+    ret.update(kwargs)
+    return ret
+
+
 @overload
 def contract_path(
     subscripts: str,
@@ -330,7 +350,7 @@ def contract_path(
         path_tuple = [tuple(range(num_ops))]
     elif isinstance(optimize, paths.PathOptimizer):
         # Custom path optimizer supplied
-        path_tuple = optimize(input_sets, output_set, size_dict, memory_arg)  # type: ignore
+        path_tuple = optimize(input_sets, output_set, size_dict, memory_arg)
     else:
         path_optimizer = paths.get_path_fn(optimize)
         path_tuple = path_optimizer(input_sets, output_set, size_dict, memory_arg)
@@ -427,6 +447,7 @@ def _einsum(*operands: Any, **kwargs: Any) -> ArrayType:
 
         einsum_str = parser.convert_to_valid_einsum_chars(einsum_str)
 
+    kwargs = _filter_einsum_defaults(kwargs)
     return fn(einsum_str, *operands, **kwargs)
 
 
@@ -906,7 +927,6 @@ def __call__(self, *arrays: ArrayType, **kwargs: Any) -> ArrayType:
             return self._contract(ops, out=out, backend=backend, evaluate_constants=evaluate_constants)
 
         except ValueError as err:
-            raise
             original_msg = str(err.args) if err.args else ""
             msg = (
                 "Internal error while evaluating `ContractExpression`. Note that few checks are performed"