iterables don't have __len__

trimesh/boolean.py

@@ -8,7 +8,7 @@
 import numpy as np
 
 from . import exceptions, interfaces
-from .typed import Callable, Iterable, Optional
+from .typed import Callable, Optional, Sequence
 
 try:
     from manifold3d import Manifold, Mesh
@@ -18,7 +18,7 @@
 
 
 def difference(
-    meshes: Iterable, engine: Optional[str] = None, check_volume: bool = True, **kwargs
+    meshes: Sequence, engine: Optional[str] = None, check_volume: bool = True, **kwargs
 ):
     """
     Compute the boolean difference between a mesh an n other meshes.
@@ -48,7 +48,7 @@ def difference(
 
 
 def union(
-    meshes: Iterable, engine: Optional[str] = None, check_volume: bool = True, **kwargs
+    meshes: Sequence, engine: Optional[str] = None, check_volume: bool = True, **kwargs
 ):
     """
     Compute the boolean union between a mesh an n other meshes.
@@ -79,7 +79,7 @@ def union(
 
 
 def intersection(
-    meshes: Iterable, engine: Optional[str] = None, check_volume: bool = True, **kwargs
+    meshes: Sequence, engine: Optional[str] = None, check_volume: bool = True, **kwargs
 ):
     """
     Compute the boolean intersection between a mesh and other meshes.
@@ -108,7 +108,7 @@ def intersection(
 
 
 def boolean_manifold(
-    meshes: Iterable,
+    meshes: Sequence,
     operation: str,
     check_volume: bool = True,
     **kwargs,
@@ -165,10 +165,10 @@ def boolean_manifold(
     return out_mesh
 
 
-def reduce_cascade(operation: Callable, items: Iterable):
+def reduce_cascade(operation: Callable, items: Sequence):
     """
     Call an operation function in a cascaded pairwise way against a
-    flat iterable of items.
+    flat list of items.
 
     This should produce the same result as `functools.reduce`
     if `operation` is commutable like addition or multiplication.