将分类的类别也应用在训练程序中，更好的解耦。

net/food_net.py

@@ -3,6 +3,7 @@ import torch.nn as nn
 import torch.nn.functional as F
 from torchvision import transforms
 from PIL import Image
+from settings import settings
 
 
 class FoodCNN(nn.Module):
@@ -50,7 +51,7 @@ class FoodCNN(nn.Module):
         # 全连接层
         self.fc1 = nn.Linear(128 * 4 * 4, 512)
         self.dropout4 = nn.Dropout(0.5)
-        self.fc2 = nn.Linear(512, 3)  # 3分类
+        self.fc2 = nn.Linear(512, settings.NUM_CLASSES)
         
     def preprocess_image(self, image):
         """