Appease the linter

src/spox/_graph.py

@@ -150,15 +150,13 @@ def __repr__(self):
 
     def __post_init__(self):
         if any(not isinstance(var, Var) for var in self._results.values()):
-            raise TypeError(
-                f"Graph results must be Vars, not {set(type(obj) for obj in self._results.values()) - {Var}}."
-            )
+            seen_types = {type(obj) for obj in self._results.values()}
+            raise TypeError(f"Graph results must be Vars, not {seen_types - {Var}}.")
         if self._arguments is not None and any(
             not isinstance(var, Var) for var in self._arguments
         ):
-            raise TypeError(
-                f"Graph results must be Vars, not {set(type(obj) for obj in self._arguments) - {Var}}."
-            )
+            seen_types = {type(obj) for obj in self._arguments}
+            raise TypeError(f"Build outputs must be Vars, not {seen_types - {Var} }.")
 
     def with_name(self, name: str) -> "Graph":
         """Return a Graph with its name set to ``name``."""

src/spox/_public.py

@@ -98,13 +98,11 @@ def build(inputs: Dict[str, Var], outputs: Dict[str, Var]) -> onnx.ModelProto:
     >>> model = build({'a': a, 'b': b, 'c': c}, {'r': q})
     """
     if not all(isinstance(var, Var) for var in inputs.values()):
-        raise TypeError(
-            f"Build inputs must be Vars, not {set(type(obj) for obj in inputs.values()) - {Var} }."
-        )
+        seen_types = {type(obj) for obj in inputs.values()}
+        raise TypeError(f"Build inputs must be Vars, not {seen_types - {Var} }.")
     if not all(isinstance(var, Var) for var in outputs.values()):
-        raise TypeError(
-            f"Build outputs must be Vars, not {set(type(obj) for obj in outputs.values()) - {Var} }."
-        )
+        seen_types = {type(obj) for obj in outputs.values()}
+        raise TypeError(f"Build outputs must be Vars, not {seen_types - {Var} }.")
     if not all(isinstance(var._op, Argument) for var in inputs.values()):
         raise TypeError(
             "Build inputs must be `Var`s constructed using the `spox.argument` function. "