Command pattern remote : start implementation

Author: dancergraham

chapter06_command/remote_undo.py

@@ -0,0 +1,41 @@
+import abc
+
+
+class Command(abc.ABC):
+    def execute(self):
+        raise NotImplementedError
+
+    def undo(self):
+        raise NotImplementedError
+
+
+class NoCommand(Command):
+    def execute(self):
+        pass
+
+    def undo(self):
+        pass
+
+
+class LightOnCommand(Command):
+    def __init__(self, light):
+        self.light = light
+
+    def execute(self):
+        self.level = self.light.getLevel()
+        self.light.on()
+ 
+    def undo(self):
+        self.light.dim(self.level)
+
+
+class LightOffCommand(Command):
+    def __init__(self, light):
+        self.light = light
+
+    def execute(self):
+        self.level = self.light.getLevel()
+        self.light.off()
+ 
+    def undo(self):
+        self.light.dim(self.level)