Add CartItemFormatter to show cart items.

src/fmt/cart_item_formatter.py

@@ -0,0 +1,32 @@
+from src.fmt.abstract_formatter import AbstractFormatter
+
+class CartItemFormatter(AbstractFormatter):
+    def format(self, item) -> str:
+        fmt, _ = self.format_and_sum(item)
+
+        return fmt
+
+    def format_and_sum(self, item) -> (str, float):
+        name = item['name']
+        price = float(item['price'])
+        count = float(item['count'])
+        total_price = price*count
+
+        return f"- {name} {count}x{price} ₴\n", total_price
+
+    def format_all(self, items: dict, header: str = "# Кошик\n\n") -> str:
+        total_sum = 0
+
+        formated_message = header
+
+        items = items['data'] if 'data' in items else items
+
+        for item in items:
+            formated_item, item_sum = self.format_and_sum(item)
+            formated_message += formated_item
+            total_sum += item_sum
+
+        formated_message += f"#### Сума: {total_sum} ₴"
+
+        return formated_message
+