fix various bugs found by the 'prospector' static-analysis tool

gpiozero/boards.py

@@ -10,11 +10,11 @@ except ImportError:
     pass
 
 from time import sleep
-from collections import namedtuple
 from itertools import repeat, cycle, chain
 from threading import Lock
 
 from .exc import (
+    DeviceClosed,
     GPIOPinMissing,
     EnergenieSocketMissing,
     EnergenieBadSocket,

gpiozero/devices.py

@@ -14,7 +14,7 @@ from itertools import chain
 from types import FunctionType
 from threading import RLock
 
-from .threads import GPIOThread, _threads_shutdown
+from .threads import _threads_shutdown
 from .mixins import (
     ValuesMixin,
     SharedMixin,
@@ -26,7 +26,6 @@ from .exc import (
     GPIOPinMissing,
     GPIOPinInUse,
     GPIODeviceClosed,
-    GPIOBadSourceDelay,
     )
 
 # Get a pin implementation to use as the default; we prefer RPi.GPIO's here

gpiozero/input_devices.py

@@ -7,12 +7,11 @@ from __future__ import (
     division,
 )
 
-import warnings
 from time import sleep, time
 from threading import Event
 
-from .exc import InputDeviceError, GPIODeviceError, DeviceClosed
-from .devices import GPIODevice, CompositeDevice
+from .exc import InputDeviceError, DeviceClosed
+from .devices import GPIODevice
 from .mixins import GPIOQueue, EventsMixin
 
 
@@ -560,7 +559,7 @@ class DistanceSensor(SmoothedInputDevice):
     def __init__(
             self, echo=None, trigger=None, queue_len=30, max_distance=1,
             threshold_distance=0.3, partial=False):
-        if not (max_distance > 0):
+        if max_distance <= 0:
             raise ValueError('invalid maximum distance (must be positive)')
         self._trigger = None
         super(DistanceSensor, self).__init__(

gpiozero/mixins.py

@@ -13,13 +13,18 @@ from functools import wraps
 from threading import Event
 from collections import deque
 try:
-    from statistics import median, mean
+    from statistics import median
 except ImportError:
-    from .compat import median, mean
+    from .compat import median
 
 from .threads import GPIOThread
-from .exc import BadEventHandler, DeviceClosed
-
+from .exc import (
+    BadEventHandler,
+    DeviceClosed,
+    GPIOBadSourceDelay,
+    GPIOBadQueueLen,
+    GPIOBadSampleWait,
+    )
 
 class ValuesMixin(object):
     """

gpiozero/output_devices.py

@@ -5,8 +5,6 @@ from __future__ import (
     division,
 )
 
-import warnings
-from time import sleep
 from threading import Lock
 from itertools import repeat, cycle, chain
 
@@ -194,7 +192,7 @@ class DigitalOutputDevice(OutputDevice):
 
     def _blink_device(self, on_time, off_time, n):
         iterable = repeat(0) if n is None else repeat(0, n)
-        for i in iterable:
+        for _ in iterable:
             self._write(True)
             if self._blink_thread.stopping.wait(on_time):
                 break

gpiozero/pins/data.py

@@ -9,7 +9,7 @@ str = type('')
 import io
 from collections import namedtuple
 
-from ..exc import PinUnknownPi, PinMultiplePins
+from ..exc import PinUnknownPi, PinMultiplePins, PinNoPins
 
 
 # Some useful constants for describing pins

gpiozero/pins/mock.py

@@ -15,7 +15,7 @@ try:
 except ImportError:
     from ..compat import isclose
 
-from . import Pin, PINS_CLEANUP
+from . import Pin
 from ..exc import PinSetInput, PinPWMUnsupported, PinFixedPull
 
 
@@ -38,7 +38,7 @@ class MockPin(Pin):
         try:
             old_pin = cls._PINS[number]
         except KeyError:
-            self = super(Pin, cls).__new__(cls)
+            self = super(MockPin, cls).__new__(cls)
             cls._PINS[number] = self
             self._number = number
             self._function = 'input'

gpiozero/pins/pigpiod.py

@@ -16,6 +16,7 @@ from ..exc import (
     PinFixedPull,
     PinInvalidPull,
     PinInvalidBounce,
+    PinInvalidState,
     )
 
 
@@ -135,7 +136,7 @@ class PiGPIOPin(Pin):
         if self._host == 'localhost':
             return "GPIO%d" % self._number
         else:
-            return "GPIO%d on %s:%d" % (self._host, self._port)
+            return "GPIO%d on %s:%d" % (self._number, self._host, self._port)
 
     @property
     def host(self):
@@ -182,7 +183,7 @@ class PiGPIOPin(Pin):
             try:
                 self._connection.set_PWM_dutycycle(self._number, int(value * 255))
             except pigpio.error:
-                raise PinInvalidValue('invalid state "%s" for pin %r' % (value, self))
+                raise PinInvalidState('invalid state "%s" for pin %r' % (value, self))
         elif self.function == 'input':
             raise PinSetInput('cannot set state of pin %r' % self)
         else:

gpiozero/pins/rpio.py

@@ -7,8 +7,6 @@ from __future__ import (
 str = type('')
 
 
-from threading import Lock
-
 import RPIO
 import RPIO.PWM
 from RPIO.Exceptions import InvalidChannelException
@@ -21,6 +19,8 @@ from ..exc import (
     PinFixedPull,
     PinInvalidPull,
     PinInvalidBounce,
+    PinInvalidState,
+    PinPWMError,
     )
 
 
@@ -126,7 +126,7 @@ class RPIOPin(Pin):
 
     def _set_state(self, value):
         if not 0 <= value <= 1:
-            raise PinInvalidValue('invalid state "%s" for pin %r' % (value, self))
+            raise PinInvalidState('invalid state "%s" for pin %r' % (value, self))
         if self._pwm:
             RPIO.PWM.clear_channel_gpio(0, self._number)
             if value == 0:

gpiozero/source_tools.py

@@ -15,8 +15,8 @@ try:
     from itertools import izip as zip
 except ImportError:
     pass
-from itertools import count, cycle
-from math import sin, cos, floor, radians
+from itertools import cycle
+from math import sin, cos, radians
 try:
     from statistics import mean
 except ImportError:

gpiozero/spi.py

@@ -184,7 +184,7 @@ class SPISoftwareBus(SharedMixin, Device):
             for write_word in data:
                 mask = 1 if self.lsb_first else 1 << (self.bits_per_word - 1)
                 read_word = 0
-                for bit in range(self.bits_per_word):
+                for _ in range(self.bits_per_word):
                     if self.mosi is not None:
                         self.mosi.value = bool(write_word & mask)
                     self.clock.on()

gpiozero/spi_devices.py

@@ -7,9 +7,9 @@ from __future__ import (
 str = type('')
 
 
-from .exc import DeviceClosed
+from .exc import DeviceClosed, InputDeviceError
 from .devices import Device
-from .spi import extract_spi_args, SPI
+from .spi import SPI
 
 
 class SPIDevice(Device):
@@ -206,7 +206,7 @@ class MCP33xx(MCP3xxx):
         data = data[-2:]
         result = ((data[0] & 63) << 7) | (data[1] >> 1)
         # Account for the sign bit
-        if self.differential and value > 4095:
+        if self.differential and result > 4095:
             result = -(8192 - result)
         assert -4096 <= result < 4096
         return result

gpiozero/threads.py

@@ -8,11 +8,6 @@ str = type('')
 
 from threading import Thread, Event
 
-from .exc import (
-    GPIOBadQueueLen,
-    GPIOBadSampleWait,
-    )
-
 
 _THREADS = set()
 def _threads_shutdown():
@@ -22,7 +17,9 @@ def _threads_shutdown():
 
 
 class GPIOThread(Thread):
-    def __init__(self, group=None, target=None, name=None, args=(), kwargs={}):
+    def __init__(self, group=None, target=None, name=None, args=(), kwargs=None):
+        if kwargs is None:
+            kwargs = {}
         self.stopping = Event()
         super(GPIOThread, self).__init__(group, target, name, args, kwargs)
         self.daemon = True