23. API - Exceptions

The following exceptions are defined by GPIO Zero. Please note that multiple inheritance is heavily used in the exception hierarchy to make testing for exceptions easier. For example, to capture any exception generated by GPIO Zero’s code:

from gpiozero import *

led = PWMLED(17)
try:
    led.value = 2
except GPIOZeroError:
    print('A GPIO Zero error occurred')

Since all GPIO Zero’s exceptions descend from GPIOZeroError, this will work. However, certain specific errors have multiple parents. For example, in the case that an out of range value is passed to OutputDevice.value you would expect a ValueError to be raised. In fact, a OutputDeviceBadValue error will be raised. However, note that this descends from both GPIOZeroError (indirectly) and from ValueError so you can still do the obvious:

from gpiozero import *

led = PWMLED(17)
try:
    led.value = 2
except ValueError:
    print('Bad value specified')

23.1. Errors

exception gpiozero.GPIOZeroError[source]

Bases: Exception

Base class for all exceptions in GPIO Zero

exception gpiozero.DeviceClosed[source]

Bases: gpiozero.exc.GPIOZeroError

Error raised when an operation is attempted on a closed device

exception gpiozero.BadEventHandler[source]

Bases: gpiozero.exc.GPIOZeroError, ValueError

Error raised when an event handler with an incompatible prototype is specified

exception gpiozero.BadWaitTime[source]

Bases: gpiozero.exc.GPIOZeroError, ValueError

Error raised when an invalid wait time is specified

exception gpiozero.BadQueueLen[source]

Bases: gpiozero.exc.GPIOZeroError, ValueError

Error raised when non-positive queue length is specified

exception gpiozero.BadPinFactory[source]

Bases: gpiozero.exc.GPIOZeroError, ImportError

Error raised when an unknown pin factory name is specified

exception gpiozero.ZombieThread[source]

Bases: gpiozero.exc.GPIOZeroError, RuntimeError

Error raised when a thread fails to die within a given timeout

exception gpiozero.CompositeDeviceError[source]

Bases: gpiozero.exc.GPIOZeroError

Base class for errors specific to the CompositeDevice hierarchy

exception gpiozero.CompositeDeviceBadName[source]

Bases: gpiozero.exc.CompositeDeviceError, ValueError

Error raised when a composite device is constructed with a reserved name

exception gpiozero.CompositeDeviceBadOrder[source]

Bases: gpiozero.exc.CompositeDeviceError, ValueError

Error raised when a composite device is constructed with an incomplete order

exception gpiozero.CompositeDeviceBadDevice[source]

Bases: gpiozero.exc.CompositeDeviceError, ValueError

Error raised when a composite device is constructed with an object that doesn’t inherit from Device

exception gpiozero.EnergenieSocketMissing[source]

Bases: gpiozero.exc.CompositeDeviceError, ValueError

Error raised when socket number is not specified

exception gpiozero.EnergenieBadSocket[source]

Bases: gpiozero.exc.CompositeDeviceError, ValueError

Error raised when an invalid socket number is passed to Energenie

exception gpiozero.SPIError[source]

Bases: gpiozero.exc.GPIOZeroError

Base class for errors related to the SPI implementation

exception gpiozero.SPIBadArgs[source]

Bases: gpiozero.exc.SPIError, ValueError

Error raised when invalid arguments are given while constructing SPIDevice

exception gpiozero.SPIBadChannel[source]

Bases: gpiozero.exc.SPIError, ValueError

Error raised when an invalid channel is given to an AnalogInputDevice

exception gpiozero.SPIFixedClockMode[source]

Bases: gpiozero.exc.SPIError, AttributeError

Error raised when the SPI clock mode cannot be changed

exception gpiozero.SPIInvalidClockMode[source]

Bases: gpiozero.exc.SPIError, ValueError

Error raised when an invalid clock mode is given to an SPI implementation

exception gpiozero.SPIFixedBitOrder[source]

Bases: gpiozero.exc.SPIError, AttributeError

Error raised when the SPI bit-endianness cannot be changed

exception gpiozero.SPIFixedSelect[source]

Bases: gpiozero.exc.SPIError, AttributeError

Error raised when the SPI select polarity cannot be changed

exception gpiozero.SPIFixedWordSize[source]

Bases: gpiozero.exc.SPIError, AttributeError

Error raised when the number of bits per word cannot be changed

exception gpiozero.SPIInvalidWordSize[source]

Bases: gpiozero.exc.SPIError, ValueError

Error raised when an invalid (out of range) number of bits per word is specified

exception gpiozero.GPIODeviceError[source]

Bases: gpiozero.exc.GPIOZeroError

Base class for errors specific to the GPIODevice hierarchy

exception gpiozero.GPIODeviceClosed[source]

Bases: gpiozero.exc.GPIODeviceError, gpiozero.exc.DeviceClosed

Deprecated descendent of DeviceClosed

exception gpiozero.GPIOPinInUse[source]

Bases: gpiozero.exc.GPIODeviceError

Error raised when attempting to use a pin already in use by another device

exception gpiozero.GPIOPinMissing[source]

Bases: gpiozero.exc.GPIODeviceError, ValueError

Error raised when a pin specification is not given

exception gpiozero.InputDeviceError[source]

Bases: gpiozero.exc.GPIODeviceError

Base class for errors specific to the InputDevice hierarchy

exception gpiozero.OutputDeviceError[source]

Bases: gpiozero.exc.GPIODeviceError

Base class for errors specified to the OutputDevice hierarchy

exception gpiozero.OutputDeviceBadValue[source]

Bases: gpiozero.exc.OutputDeviceError, ValueError

Error raised when value is set to an invalid value

exception gpiozero.PinError[source]

Bases: gpiozero.exc.GPIOZeroError

Base class for errors related to pin implementations

exception gpiozero.PinInvalidFunction[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when attempting to change the function of a pin to an invalid value

exception gpiozero.PinInvalidState[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when attempting to assign an invalid state to a pin

exception gpiozero.PinInvalidPull[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when attempting to assign an invalid pull-up to a pin

exception gpiozero.PinInvalidEdges[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when attempting to assign an invalid edge detection to a pin

exception gpiozero.PinInvalidBounce[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when attempting to assign an invalid bounce time to a pin

exception gpiozero.PinSetInput[source]

Bases: gpiozero.exc.PinError, AttributeError

Error raised when attempting to set a read-only pin

exception gpiozero.PinFixedPull[source]

Bases: gpiozero.exc.PinError, AttributeError

Error raised when attempting to set the pull of a pin with fixed pull-up

exception gpiozero.PinEdgeDetectUnsupported[source]

Bases: gpiozero.exc.PinError, AttributeError

Error raised when attempting to use edge detection on unsupported pins

exception gpiozero.PinUnsupported[source]

Bases: gpiozero.exc.PinError, NotImplementedError

Error raised when attempting to obtain a pin interface on unsupported pins

exception gpiozero.PinSPIUnsupported[source]

Bases: gpiozero.exc.PinError, NotImplementedError

Error raised when attempting to obtain an SPI interface on unsupported pins

exception gpiozero.PinPWMError[source]

Bases: gpiozero.exc.PinError

Base class for errors related to PWM implementations

exception gpiozero.PinPWMUnsupported[source]

Bases: gpiozero.exc.PinPWMError, AttributeError

Error raised when attempting to activate PWM on unsupported pins

exception gpiozero.PinPWMFixedValue[source]

Bases: gpiozero.exc.PinPWMError, AttributeError

Error raised when attempting to initialize PWM on an input pin

exception gpiozero.PinUnknownPi[source]

Bases: gpiozero.exc.PinError, RuntimeError

Error raised when gpiozero doesn’t recognize a revision of the Pi

exception gpiozero.PinMultiplePins[source]

Bases: gpiozero.exc.PinError, RuntimeError

Error raised when multiple pins support the requested function

exception gpiozero.PinNoPins[source]

Bases: gpiozero.exc.PinError, RuntimeError

Error raised when no pins support the requested function

exception gpiozero.PinInvalidPin[source]

Bases: gpiozero.exc.PinError, ValueError

Error raised when an invalid pin specification is provided

23.2. Warnings

exception gpiozero.GPIOZeroWarning[source]

Bases: Warning

Base class for all warnings in GPIO Zero

exception gpiozero.DistanceSensorNoEcho[source]

Bases: gpiozero.exc.GPIOZeroWarning

Warning raised when the distance sensor sees no echo at all

exception gpiozero.SPIWarning[source]

Bases: gpiozero.exc.GPIOZeroWarning

Base class for warnings related to the SPI implementation

exception gpiozero.SPISoftwareFallback[source]

Bases: gpiozero.exc.SPIWarning

Warning raised when falling back to the SPI software implementation

exception gpiozero.PinWarning[source]

Bases: gpiozero.exc.GPIOZeroWarning

Base class for warnings related to pin implementations

exception gpiozero.PinFactoryFallback[source]

Bases: gpiozero.exc.PinWarning

Warning raised when a default pin factory fails to load and a fallback is tried

exception gpiozero.PinNonPhysical[source]

Bases: gpiozero.exc.PinWarning

Warning raised when a non-physical pin is specified in a constructor

exception gpiozero.ThresholdOutOfRange[source]

Bases: gpiozero.exc.GPIOZeroWarning

Warning raised when a threshold is out of range specified by min and max values

exception gpiozero.CallbackSetToNone[source]

Bases: gpiozero.exc.GPIOZeroWarning

Warning raised when a callback is set to None when its previous value was None