diff --git a/gpiozero/devices.py b/gpiozero/devices.py
index 22d4048..67c90c8 100644
--- a/gpiozero/devices.py
+++ b/gpiozero/devices.py
@@ -25,6 +25,8 @@ class GPIODevice(object):
 
 
 _GPIO_THREADS = set()
+
+
 def _gpio_threads_shutdown():
     while _GPIO_THREADS:
         for t in _GPIO_THREADS.copy():
@@ -46,4 +48,3 @@ class GPIOThread(Thread):
         self.stopping.set()
         self.join()
         _GPIO_THREADS.discard(self)
-
diff --git a/gpiozero/input_devices.py b/gpiozero/input_devices.py
index 0fbec6a..4490a22 100644
--- a/gpiozero/input_devices.py
+++ b/gpiozero/input_devices.py
@@ -22,7 +22,8 @@ class InputDevice(GPIODevice):
         if pull_up:
             self._active_state = 0
             self._inactive_state = 1
-        GPIO.setup(pin, GPIO.IN, (GPIO.PUD_DOWN, GPIO.PUD_UP)[pull_up])
+        pull = GPIO.PUD_UP if pull_up else GPIO.PUD_DOWN
+        GPIO.setup(pin, GPIO.IN, pull)
 
     @property
     def pull_up(self):
@@ -68,25 +69,29 @@ class MotionSensor(InputDevice):
 
     def _get_sample_rate(self):
         return self._sample_rate
+
     def _set_sample_rate(self, value):
         if value <= 0:
             raise InputDeviceError('sample_rate must be greater than zero')
         self._sample_rate = value
+
     sample_rate = property(_get_sample_rate, _set_sample_rate)
 
     def _get_threshold(self):
         return self._threshold
+
     def _set_threshold(self, value):
         if value < 0:
             raise InputDeviceError('threshold must be zero or more')
         self._threshold = value
+
     threshold = property(_get_threshold, _set_threshold)
 
     def _fill_queue(self):
         while (
-                not self._queue_thread.stopping.wait(1 / self.sample_rate) and
-                len(self._queue) < self._queue.maxlen
-            ):
+            not self._queue_thread.stopping.wait(1 / self.sample_rate) and
+            len(self._queue) < self._queue.maxlen
+        ):
             self._queue.append(self.is_active)
         self._queue_full.set()
         while not self._queue_thread.stopping.wait(1 / self.sample_rate):
@@ -104,7 +109,9 @@ class LightSensor(InputDevice):
         self.threshold = threshold
         self.partial = partial
         self._charged = Event()
-        GPIO.add_event_detect(self.pin, GPIO.RISING, lambda channel: self._charged.set())
+        GPIO.add_event_detect(
+            self.pin, GPIO.RISING, lambda channel: self._charged.set()
+        )
         self._queue = deque(maxlen=queue_len)
         self._queue_full = Event()
         self._queue_thread = GPIOThread(target=self._fill_queue)
@@ -124,7 +131,10 @@ class LightSensor(InputDevice):
         if not self.partial:
             self._queue_full.wait()
         try:
-            return 1.0 - (sum(self._queue) / len(self._queue)) / self.darkness_time
+            return (
+                1.0 - (sum(self._queue) / len(self._queue)) /
+                self.darkness_time
+            )
         except ZeroDivisionError:
             # No data == no light
             return 0.0
@@ -135,14 +145,17 @@ class LightSensor(InputDevice):
 
     def _get_when_light(self):
         return self._when_light
+
     def _set_when_light(self, value):
         if not callable(value) and value is not None:
             raise InputDeviceError('when_light must be None or a function')
         self._when_light = value
+
     when_light = property(_get_when_light, _set_when_light)
 
     def _get_when_dark(self):
         return self._when_dark
+
     def _set_when_dark(self, value):
         if not callable(value) and value is not None:
             raise InputDeviceError('when_dark must be None or a function')
@@ -156,27 +169,29 @@ class LightSensor(InputDevice):
 
     def _get_darkness_time(self):
         return self._darkness_time
+
     def _set_darkness_time(self, value):
         if value <= 0.0:
             raise InputDeviceError('darkness_time must be greater than zero')
         self._darkness_time = value
         # XXX Empty the queue and restart the thread
+
     darkness_time = property(_get_darkness_time, _set_darkness_time)
 
     def _get_threshold(self):
         return self._threshold
+
     def _set_threshold(self, value):
         if value < 0:
             raise InputDeviceError('threshold must be zero or more')
         self._threshold = value
+
     threshold = property(_get_threshold, _set_threshold)
 
     def _fill_queue(self):
         try:
-            while (
-                    not self._queue_thread.stopping.is_set() and
-                    len(self._queue) < self._queue.maxlen
-                ):
+            while (not self._queue_thread.stopping.is_set() and
+                    len(self._queue) < self._queue.maxlen):
                 self._queue.append(self._time_charging())
                 if self.partial:
                     self._fire_events()
@@ -213,9 +228,8 @@ class LightSensor(InputDevice):
             if self.when_dark:
                 self.when_dark()
 
+
 class TemperatureSensor(W1ThermSensor):
     @property
     def value(self):
         return self.get_temperature()
-
-
diff --git a/gpiozero/output_devices.py b/gpiozero/output_devices.py
index 0bdd42a..3a5840e 100644
--- a/gpiozero/output_devices.py
+++ b/gpiozero/output_devices.py
@@ -27,7 +27,9 @@ class LED(OutputDevice):
 
     def blink(self, on_time=1, off_time=1):
         self._stop_blink()
-        self._blink_thread = GPIOThread(target=self._blink_led, args=(on_time, off_time))
+        self._blink_thread = GPIOThread(
+            target=self._blink_led, args=(on_time, off_time)
+        )
         self._blink_thread.start()
 
     def _stop_blink(self):
@@ -64,9 +66,7 @@ class Motor(OutputDevice):
 class Robot(object):
     def __init__(self, left=None, right=None):
         if not all([left, right]):
-            raise GPIODeviceError(
-                'left and right pins must be provided'
-            )
+            raise GPIODeviceError('left and right pins must be provided')
 
         self._left = Motor(left)
         self._right = Motor(right)