[K-LMS Scheduler] fix import (#191)

src/diffusers/__init__.py

@@ -31,13 +31,13 @@ from .schedulers import (
 
 if is_scipy_available():
     from .schedulers import LMSDiscreteScheduler
+else:
+    from .utils.dummy_scipy_objects import *
 
 from .training_utils import EMAModel
 
 
 if is_transformers_available():
     from .pipelines import LDMTextToImagePipeline, StableDiffusionPipeline
-
-
 else:
     from .utils.dummy_transformers_objects import *

src/diffusers/schedulers/__init__.py

@@ -28,3 +28,5 @@ from .scheduling_utils import SchedulerMixin
 
 if is_scipy_available():
     from .scheduling_lms_discrete import LMSDiscreteScheduler
+else:
+    from ..utils.dummy_scipy_objects import *

src/diffusers/schedulers/scheduling_pndm.py

@@ -120,6 +120,7 @@ class PNDMScheduler(SchedulerMixin, ConfigMixin):
 
         self.timesteps = self.prk_timesteps + self.plms_timesteps
 
+        self.ets = []
         self.counter = 0
         self.set_format(tensor_format=self.tensor_format)
 

src/diffusers/utils/dummy_scipy_objects.py

@@ -3,7 +3,7 @@
 from ..utils import DummyObject, requires_backends
 
 
-class LmsDiscreteScheduler(metaclass=DummyObject):
+class LMSDiscreteScheduler(metaclass=DummyObject):
     _backends = ["scipy"]
 
     def __init__(self, *args, **kwargs):