added definition of tweet class

code/classes.py

@@ -0,0 +1,40 @@
+from pydantic import BaseModel, validator
+from typing import Union, List, Optional
+from datetime import datetime
+from PIL import Image
+from io import BytesIO
+
+class Tweet(BaseModel):
+    account: str
+    url: str
+    time: datetime
+    text: str
+    images: Optional[Union[List[Image.Image], List[BytesIO]]]
+    video: Optional[str]
+
+    class Config:
+        arbitrary_types_allowed = True
+    
+    @validator('images', each_item=True)
+    def parse_image(cls, v):
+        if isinstance(v, BytesIO):
+            v = Image.open(v)
+        return v
+    
+    def parse_images(self):
+        for i in range(len(self.images)):
+            self.images[i] = Image.open(self.images[i])
+    
+    def as_db_dict(self):
+        """Convert to database dictionary"""
+        d = self.dict()
+        d['time'] = d['time'].strftime('%Y-%m-%d %H:%M:%S')
+        img_list = list()
+        for img in d['images']:
+            if isinstance(img, BytesIO):
+                img = Image.open(img)
+            buf = BytesIO()
+            img.save(buf, format='PNG')
+            img_list.append(buf.getvalue())
+        d['images'] = img_list
+        return d