USD find all used assets in Stage or Layer using Python - e.g. findin all used textures

usd_python_list_all_used_assets.py

from pxr import UsdUtils, Sdf

stage = hou.pwd().editableStage()

# Given a Sdf.Layer you can use UsdUtils.ComputeAllDependencies
# which returns the layers, assets and any unresolved paths
layer = stage.Flatten()
layers, assets, unresolved_paths = UsdUtils.ComputeAllDependencies(layer.identifier)
for path in assets:
    print(path)
    
# Another approach is traversing the Usd.Stage or Sdf.Layer for
# any property that is of type `Sdf.ValueTypeNames.Asset` or
# where the Sdf.AttributeSpec is of type name "asset"
# E.g. via layer traversal
def trav(path):
    if not path.IsPropertyPath():
        return
        
    spec = layer.GetObjectAtPath(path)
    if not isinstance(spec, Sdf.AttributeSpec):
        return
    
    if spec.typeName != "asset":
        return
        
    print(path)

layer.Traverse("/", trav)


# Or via the traversing composed stage.
# Note: As per the USD docs for UsdAttribute this might be best to do within a ArResolverScopedCache
#     https://openusd.org/dev/api/class_usd_attribute.html
#     https://openusd.org/dev/api/class_ar_resolver_scoped_cache.html
for prim in stage.Traverse():
    for attr in prim.GetAuthoredAttributes():
        if attr.GetTypeName() != "asset":
            continue
            
        print(attr.Get())