Strange code in altwcs about stwcs HOT 7 CLOSED

Git blame (if it helps understand the context):

0f3e78c

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I think this code was intended to pick a wcsname for the WCS to be archived based on the last archived WCS when user did not provide wcsname or when the primary WCS does not have a name.

I'll make a PR to fix the code which also has another bug at

wnames is a dictionary while wname should be a string.

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@mcara I doubt that was the intention because ... why? Perhaps it was only meant to create a default name.

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Hm, if only creating a default name, why even use a loop with IF?

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@stsci-hack Could you please take a look at this?

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Best guess: a clumsy attempt to loop over the WCSNAMES in reverse order with the intended syntax most likely supposed to be 'a[::-1]'. It mostly worked since it pulled and checked the last key which was most often the desired default WCS since it was the last one archived. So, feel free to revise or remove as needed.

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I believe https://github.com/spacetelescope/stwcs/pull/134/files#diff-516dcd10bb4c104d97362626d506e981R127 does exactly that:

wname = sorted(wnames.items(), key=lambda x: x[0])[-1][1]

Sort dictionary items by keys and pick the value of the last item (key).

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