factory

test2.py

+from abc import ABC, abstractmethod
+
+
+class SellStrategy(ABC):
+
+
+    @abstractmethod
+    def sell_crypto(self, x: float, y: float):
+        """sells crypto and returns new x"""
+
+
+class SellAll(SellStrategy):
+
+    def sell_crypto(self, x: float, y: float):
+
+        btc = 0
+        usdt = x * y
+        return {"btc": btc, "usdt": usdt}
+
+
+class SellHalf(SellStrategy):
+
+    def sell_crypto(self, x: float, y: float):
+
+        btc = x / 2
+        usdt = (x / 2) * y
+        return {"btc": btc, "usdt": usdt}
+
+
+class SellLittle(SellStrategy):
+
+    def sell_crypto(self, x: float, y: float):
+
+        btc = x * 0.9
+        usdt = (x * 0.1) * y
+        return {"btc": btc, "usdt": usdt}
+
+
+class TradingApp:
+    assets = {"btc": 100, "usdt": 0}
+    y = 30000
+
+    def sell_order(self, sell_decision: SellStrategy):
+        self.assets = sell_decision.sell_crypto(self.assets["btc"], self.y)
+        return self.assets
+
+
+A = TradingApp()
+
+assets = A.sell_order(SellAll())
+print(assets)