update device class to use decorators

device/device.py

@@ -20,9 +20,17 @@ class Device:
         # write voltage to device
         self.__voltage = new_voltage
 
+    @property
+    def voltage(self):
+        return self._get_voltage()
+
+    @voltage.setter
+    def voltage(self, new_voltage):
+        self._set_voltage(new_voltage)
+
     def _get_current(self):
         # read current from device
-        current = self.__curent
+        current = self.__current
         self.current = current
         return current
 
@@ -30,8 +38,22 @@ class Device:
         # write current to device
         self.__current = new_current
 
+    @property
+    def current(self):
+        return self._get_current()
+
+    @current.setter
+    def current(self, new_current):
+        self._set_current(new_current)
+
     def _calculate_resistance(self):
+        if self.current == 0:
+            return float('inf')
         current = self.current
         voltage = self.voltage
         resistance = voltage / current
         return resistance
+
+    @property
+    def resistance(self):
+        return self._calculate_resistance()