start doing turtle task

equipment/turtle_device.py

@@ -1,8 +0,0 @@
-from turtle import Turtle
-from controls.device import SynchronyDevice
-
-class TurtleDevice(SynchronyDevice):
-    pass  # TODO(Homework #3)
-
-
-

turtle/controls/device.py

@@ -1,12 +1,16 @@
 from dataclasses import dataclass
 from typing import Optional, Collection, Any
-from abc import abstractmethod
-
-class DeviceLifecycleState:
-    pass  # TODO(Homework #3)
+from abc import ABC, abstractmethod, abstractproperty
+from enum import Enum
 
 
-class DevaceError(Exception):
+class DeviceLifecycleState(Enum):
+    INIT = 0
+    OPEN = 1
+    CLOSE = 2
+
+
+class DeviceError(Exception):
     pass
 
 
@@ -33,8 +37,7 @@ class ActionDescriptor:
     info: Optional[str] = None
 
 
-class Device:
-    # TODO(Homework #3)
+class Device(ABC):
     _state = DeviceLifecycleState.INIT
 
     @property
@@ -44,9 +47,11 @@ class Device:
     def close(self):
         self._state = DeviceLifecycleState.CLOSE
 
+    @abstractproperty
     def trait_descriptors(self) -> Collection[TraitDescriptor]:
         pass
 
+    @abstractproperty
     def action_descriptors(self) -> Collection[ActionDescriptor]:
         pass
 

turtle/equipment/turtle_device.py

@@ -0,0 +1,34 @@
+from turtle import Turtle
+from typing import Optional, Collection, Any
+from controls.device import SynchronyDevice
+from controls.device import TraitDescriptor
+from controls.device import ActionDescriptor
+
+
+class TurtleDevice(SynchronyDevice):
+    def open(self):
+        self.turtle = Turtle()
+        super().open()
+
+    def close(self):
+        self.turtle.clear()
+        super().close()
+
+    def trait_descriptors(self) -> Collection[TraitDescriptor]:
+        pass
+
+    def action_descriptors(self) -> Collection[ActionDescriptor]:
+        pass
+
+    def __getitem__(self, trait_name: str) -> Optional[Any]:
+        """Return logical state of trait `trait_name`."""
+        pass
+
+    def read(self, trait_name: str) -> Any:
+        raise NonReadableTrait
+
+    def write(self, trait_name: str, value: Any) -> bool:
+        self.turtle.write()
+
+    def invalidate(self, trait_name: str):
+        pass