get_microphone(), get_speaker(): Improved comparison between the call parameter "id" and existing device names

[adeuring]

This PR fixes the problems mentioned in #146 , "Problems with the "fuzzy matcher" in get_microphone().

The changes are a bit longer than I expected at first, but anyway:

I moved the functions _match_device() from the modules coreaudio and mediafoundation into a new module utils so that the same implementation can be used for all platforms. pulseaudio has of course a similar change to use utils.match_device().

Changes to match_device():

1. I added another name lookup in match_device(): Before the function checks if the call parameter id is a substring of one of the device names, it checks if the call parameter identical with any of the device names. While I also added your suggestion to separate real and loopback devices in name lookups (see below), there still is at least in theory still a corner case without this "name identity lookup": A loopback device could have a name that is the substring of a real microphone. Admitted, not very likely, but you never know ;) If only a substring lookup for the loopback device is done where real devices have precedence, the loopback device would not be returned. (See also the diff of test_soundcard, line 229. That test will fail without the additional "full name check".)
2. Symbols with a special meaning in regexes are escaped if they appear in the call parameter `id* . (I'd appreciate a double-check if I got all relevant symbols when I read https://docs.python.org/3/library/re.html#regular-expression-syntax ...)

Final note: I am not too happy with the tests I wrote: I think it would be nice to have some device names and IDs from Windows and MacOS too in the tests. Problem, as already mentioned in #146 : I have neither a Mac nor a machine with a Windows installation. But I'm happy to add device names from MacOS/Windows if I get some examples.

[bastibe]

That's a great addition, thank you! And you factored out the common code as well, and added some platform-independent tests! Thank you so much!

Here are pairs of device IDs, device names, and isloopback on my Windows box:

Mics:

{0.0.0.00000000}.{075a16c1-576e-419e-84c1-70d03e0d6276} BenQ PD2700U (Intel(R) Display-Audio) True
{0.0.0.00000000}.{27473622-d168-4a9c-87c5-230c148c09c9} Lautsprecher (4- Samson GoMic) True
{0.0.0.00000000}.{f08702cd-ee32-4c95-ac85-ff21a9d4d8ec} Lautsprecher (Realtek(R) Audio) True
{0.0.1.00000000}.{041738dd-f5c5-485e-a5da-c5f34c35171f} Digitale Audioschnittstelle (Cam Link 4K) False
{0.0.1.00000000}.{be293184-38fd-41cb-9c50-27971414ac0b} Stereomix (Realtek(R) Audio) False
{0.0.1.00000000}.{c0c95239-3a6c-427b-a788-9caeb13a7f43} Mikrofonarray (Realtek(R) Audio) False
{0.0.1.00000000}.{e31e9915-d1b1-49dd-88bf-3cc232ec2a11} Mikrofon (4- Samson GoMic) False

Speakers:

{0.0.0.00000000}.{075a16c1-576e-419e-84c1-70d03e0d6276} BenQ PD2700U (Intel(R) Display-Audio)
{0.0.0.00000000}.{27473622-d168-4a9c-87c5-230c148c09c9} Lautsprecher (4- Samson GoMic)
{0.0.0.00000000}.{f08702cd-ee32-4c95-ac85-ff21a9d4d8ec} Lautsprecher (Realtek(R) Audio)

[bastibe]

And a few id/names from macOS:
Mics (macOS does not support loopbacks at the moment):

42 Built-in Microphone False
59 Samson GoMic False

Speakers:

49 Built-in Output
59 Samson GoMic

[bastibe]

I think I agree with your assessment that the two-stage search of no-loopbacks before loopbacks is actually overkill. Your first solution with the substring match is perfectly acceptable to me, and much more elegant.

I would probably add a note in the docstring of get_* to the effect of "For certain device names, the fuzzy search may be ambiguous. In that case, search by device ID (mic.id/speaker.id), or manually search all_microphones/all_speakers to find the device in question".

[adeuring]

Thanks for the review! I think I addressed all issues you mentioned. I kept though the "two-stage search" for now as it can in some cases make sense, I believe.

Also thanks for the examples of Windows and MacOS IDs/device names. Added to the test data.

[bastibe]

This looks good to me! I'll test this code on Windows and macOS next week, and then we can merge!

Thank you very much!