Force map.meta to be a MetaDict #4476
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nabobalis
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| def test_bad_header_final_fallback(): | ||
| # Checks that if a WCS cannot be constructed from the | ||
| # header, a warning is raised and a simple WCS is created | ||
| # instead |
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As far as I can tell, as long as everything in the header is a string (which is now mandated), astropy will happily parse it and we will never get to the point where a simple WCS needs to be created. Warnings like
VerifyWarning("Keyword name '#none' is greater than 8 characters or contains characters not allowed by the FITS standard; a HIERARCH card will be created.")
are raised when I try and put some gibberish in a header. So I've removed this test. I suppose there's no harm in have the fallback, but I can't think of anything that will actually exercise it.
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Interesting, and it's good that this improves the validation and makes the error better.
I think there is a class of errors for which the fallback in GenericMap is still useful and might not be being tested, which is a valid FITS header but an invalid WCS. i.e. something which when passed to astropy.wcs.WCS errors because of some issue (like invalid values etc).
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I'm still struggling to find something that trips the warning. Changing ctype, crval, crpix, or cdelt to garbage values just makes the checks below error instead. I've also tried with the header (I think a WISPR one?) that caused this warning to be put in the code, and that doesn't trigger the warning either.
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I feel like this is a very slight API change, backporting this might be off the cards. |
This is a requirement for #4467.
Previously it was possible that
map.metacould just be a simple dict if a map was constructed withmap.GenericMap. This bringsGenericMapin line with the map factory (ie.Map) and forcesmetato always be aMetaDict.