Fixed pcan Unpack error by FedericoSpada · Pull Request #1767

Fixed pcan Unpack error by FedericoSpada · Pull Request #1767 · hardbyte/python-can

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One of my colleagues encountered a "not enough values to unpack" error while scanning for connected dongles with PCAN drivers installed.
I couldn't replicate the error on my computer after installing the latest PCAN drivers. Still, analysing the instruction that raised that error, it seems that PCANBasic.GetValue() returned a wrong Tuple for a specific error condition.
That method must always return a Tuple with 2 elements, otherwise PcanBus._detect_available_configs() raises a "not enough values to unpack" error at line 718.

PCANBasic.GetValue() must always return a Tuple with 2 elements, otherwise PcanBus._detect_available_configs() raises a "not enough values to unpack" error at line 718.

		res = self.GetValue(Channel, PCAN_ATTACHED_CHANNELS_COUNT)
		if TPCANStatus(res[0]) != PCAN_ERROR_OK:
		return (TPCANStatus(res[0]),)
		return TPCANStatus(res[0]), ()

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	return TPCANStatus(res[0]), ()
	return TPCANStatus(res[0]), None

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Since you expect to receive an Iterable, returning an empty tuple is better so you don't have to check if it is "None" before using it in a For loop.

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This is the error case. There is no valid result, so it is not used here:

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2 participants