place ependency scipy from runtime to optional

mmcls/datasets/__init__.py

@@ -12,7 +12,7 @@
 from .mnist import MNIST, FashionMNIST
 from .multi_label import MultiLabelDataset
 from .samplers import DistributedSampler, RepeatAugSampler
-from .stanford_car import StanfordCars
+from .stanford_cars import StanfordCars
 from .voc import VOC
 
 __all__ = [

mmcls/datasets/stanford_car.py → mmcls/datasets/stanford_cars.py

@@ -3,7 +3,6 @@
 from typing import Optional
 
 import numpy as np
-import scipy.io as sio
 
 from .base_dataset import BaseDataset
 from .builder import DATASETS
@@ -184,6 +183,12 @@ def __init__(self,
             **kwargs)
 
     def load_annotations(self):
+        try:
+            import scipy.io as sio
+        except ImportError:
+            raise ImportError(
+                'please run `pip install scipy` to install package `scipy`.')
+
         data_infos = []
         if self.test_mode:
             data = sio.loadmat(self.test_ann_file)

requirements/optional.txt

@@ -2,3 +2,4 @@ albumentations>=0.3.2 --no-binary qudida,albumentations
 colorama
 requests
 rich
+scipy

requirements/runtime.txt

@@ -1,4 +1,3 @@
 matplotlib
 numpy
 packaging
-scipy

tests/test_data/test_datasets/test_common.py

@@ -7,7 +7,6 @@
 from unittest.mock import patch
 
 import numpy as np
-import scipy.io as sio
 import torch
 
 from mmcls.datasets import DATASETS
@@ -827,6 +826,12 @@ def setUpClass(cls) -> None:
         cls.DEFAULT_ARGS = dict(
             data_prefix=cls.data_prefix, pipeline=[], test_mode=False)
 
+        try:
+            import scipy.io as sio
+        except ImportError:
+            raise ImportError(
+                'please run `pip install scipy` to install package `scipy`.')
+
         sio.savemat(
             cls.train_ann_file, {
                 'annotations': [(