[Dummy imports] Better error message (#795)

* [Dummy imports] Better error message

* Test: load pipeline with LMS scheduler.

Fails with a cryptic message if scipy is not installed.

* Correct
Co-authored-by: Pedro Cuenca <pedro@huggingface.co>

src/diffusers/pipeline_utils.py

@@ -49,6 +49,7 @@ if is_transformers_available():
 
 INDEX_FILE = "diffusion_pytorch_model.bin"
 CUSTOM_PIPELINE_FILE_NAME = "pipeline.py"
+DUMMY_MODULES_FOLDER = "diffusers.utils"
 
 
 logger = logging.get_logger(__name__)
@@ -467,9 +468,20 @@ class DiffusionPipeline(ConfigMixin):
                     if issubclass(class_obj, class_candidate):
                         load_method_name = importable_classes[class_name][1]
 
-                load_method = getattr(class_obj, load_method_name)
+                if load_method_name is None:
+                    none_module = class_obj.__module__
+                    if none_module.startswith(DUMMY_MODULES_FOLDER) and "dummy" in none_module:
+                        # call class_obj for nice error message of missing requirements
+                        class_obj()
+
+                    raise ValueError(
+                        f"The component {class_obj} of {pipeline_class} cannot be loaded as it does not seem to have"
+                        f" any of the loading methods defined in {ALL_IMPORTABLE_CLASSES}."
+                    )
 
+                load_method = getattr(class_obj, load_method_name)
                 loading_kwargs = {}
+
                 if issubclass(class_obj, torch.nn.Module):
                     loading_kwargs["torch_dtype"] = torch_dtype
                 if issubclass(class_obj, diffusers.OnnxRuntimeModel):

src/diffusers/utils/dummy_flax_and_transformers_objects.py

@@ -9,3 +9,11 @@ class FlaxStableDiffusionPipeline(metaclass=DummyObject):
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax", "transformers"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax", "transformers"])

src/diffusers/utils/dummy_flax_objects.py

@@ -10,6 +10,14 @@ class FlaxModelMixin(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxUNet2DConditionModel(metaclass=DummyObject):
     _backends = ["flax"]
@@ -17,6 +25,14 @@ class FlaxUNet2DConditionModel(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxAutoencoderKL(metaclass=DummyObject):
     _backends = ["flax"]
@@ -24,6 +40,14 @@ class FlaxAutoencoderKL(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxDiffusionPipeline(metaclass=DummyObject):
     _backends = ["flax"]
@@ -31,6 +55,14 @@ class FlaxDiffusionPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxDDIMScheduler(metaclass=DummyObject):
     _backends = ["flax"]
@@ -38,6 +70,14 @@ class FlaxDDIMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxDDPMScheduler(metaclass=DummyObject):
     _backends = ["flax"]
@@ -45,6 +85,14 @@ class FlaxDDPMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxKarrasVeScheduler(metaclass=DummyObject):
     _backends = ["flax"]
@@ -52,6 +100,14 @@ class FlaxKarrasVeScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxLMSDiscreteScheduler(metaclass=DummyObject):
     _backends = ["flax"]
@@ -59,6 +115,14 @@ class FlaxLMSDiscreteScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxPNDMScheduler(metaclass=DummyObject):
     _backends = ["flax"]
@@ -66,6 +130,14 @@ class FlaxPNDMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxSchedulerMixin(metaclass=DummyObject):
     _backends = ["flax"]
@@ -73,9 +145,25 @@ class FlaxSchedulerMixin(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
 
 class FlaxScoreSdeVeScheduler(metaclass=DummyObject):
     _backends = ["flax"]
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["flax"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["flax"])

src/diffusers/utils/dummy_pt_objects.py

@@ -10,6 +10,14 @@ class ModelMixin(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class AutoencoderKL(metaclass=DummyObject):
     _backends = ["torch"]
@@ -17,6 +25,14 @@ class AutoencoderKL(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class UNet2DConditionModel(metaclass=DummyObject):
     _backends = ["torch"]
@@ -24,6 +40,14 @@ class UNet2DConditionModel(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class UNet2DModel(metaclass=DummyObject):
     _backends = ["torch"]
@@ -31,6 +55,14 @@ class UNet2DModel(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class VQModel(metaclass=DummyObject):
     _backends = ["torch"]
@@ -38,6 +70,14 @@ class VQModel(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 def get_constant_schedule(*args, **kwargs):
     requires_backends(get_constant_schedule, ["torch"])
@@ -73,6 +113,14 @@ class DiffusionPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class DDIMPipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -80,6 +128,14 @@ class DDIMPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class DDPMPipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -87,6 +143,14 @@ class DDPMPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class KarrasVePipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -94,6 +158,14 @@ class KarrasVePipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class LDMPipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -101,6 +173,14 @@ class LDMPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class PNDMPipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -108,6 +188,14 @@ class PNDMPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class ScoreSdeVePipeline(metaclass=DummyObject):
     _backends = ["torch"]
@@ -115,6 +203,14 @@ class ScoreSdeVePipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class DDIMScheduler(metaclass=DummyObject):
     _backends = ["torch"]
@@ -122,6 +218,14 @@ class DDIMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class DDPMScheduler(metaclass=DummyObject):
     _backends = ["torch"]
@@ -129,6 +233,14 @@ class DDPMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class KarrasVeScheduler(metaclass=DummyObject):
     _backends = ["torch"]
@@ -136,6 +248,14 @@ class KarrasVeScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class PNDMScheduler(metaclass=DummyObject):
     _backends = ["torch"]
@@ -143,6 +263,14 @@ class PNDMScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class SchedulerMixin(metaclass=DummyObject):
     _backends = ["torch"]
@@ -150,6 +278,14 @@ class SchedulerMixin(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class ScoreSdeVeScheduler(metaclass=DummyObject):
     _backends = ["torch"]
@@ -157,9 +293,25 @@ class ScoreSdeVeScheduler(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
 
 class EMAModel(metaclass=DummyObject):
     _backends = ["torch"]
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])

src/diffusers/utils/dummy_torch_and_scipy_objects.py

@@ -9,3 +9,11 @@ class LMSDiscreteScheduler(metaclass=DummyObject):
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "scipy"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "scipy"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "scipy"])

src/diffusers/utils/dummy_torch_and_transformers_and_onnx_objects.py

@@ -9,3 +9,11 @@ class StableDiffusionOnnxPipeline(metaclass=DummyObject):
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "transformers", "onnx"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers", "onnx"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers", "onnx"])

src/diffusers/utils/dummy_torch_and_transformers_objects.py

@@ -10,6 +10,14 @@ class LDMTextToImagePipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "transformers"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
 
 class StableDiffusionImg2ImgPipeline(metaclass=DummyObject):
     _backends = ["torch", "transformers"]
@@ -17,6 +25,14 @@ class StableDiffusionImg2ImgPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "transformers"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
 
 class StableDiffusionInpaintPipeline(metaclass=DummyObject):
     _backends = ["torch", "transformers"]
@@ -24,9 +40,25 @@ class StableDiffusionInpaintPipeline(metaclass=DummyObject):
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "transformers"])
 
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
 
 class StableDiffusionPipeline(metaclass=DummyObject):
     _backends = ["torch", "transformers"]
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, ["torch", "transformers"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])

tests/test_pipelines.py

@@ -492,6 +492,12 @@ class PipelineFastTests(unittest.TestCase):
         assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
         assert np.abs(image_from_tuple_slice.flatten() - expected_slice).max() < 1e-2
 
+    def test_from_pretrained_error_message_uninstalled_packages(self):
+        # TODO(Patrick, Pedro) - need better test here for the future
+        pipe = StableDiffusionPipeline.from_pretrained("hf-internal-testing/tiny-stable-diffusion-lms-pipe")
+        assert isinstance(pipe, StableDiffusionPipeline)
+        assert isinstance(pipe.scheduler, LMSDiscreteScheduler)
+
     def test_stable_diffusion_k_lms(self):
         device = "cpu"  # ensure determinism for the device-dependent torch.Generator
         unet = self.dummy_cond_unet

utils/check_dummies.py

@@ -38,6 +38,14 @@ class {0}(metaclass=DummyObject):
 
     def __init__(self, *args, **kwargs):
         requires_backends(self, {1})
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, {1})
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, {1})
 """