[AstroPy] PR 3655 (Fortran-style and large exponents in ascii.io)

[Derek Homeier]

Hi,

is there anyone else I should send this to regarding the PR?

> first, this is an invitation to review the pull request for Fortran-style exponent character support
> 
> https://github.com/astropy/astropy/pull/3655
> 
> which has been dormant for a fairly long time because of some test crashes on travis.
> I’ve noticed far too late that long exponents (> 3 digits) already were flagged as a known
> cause of segfaults on travis, and therefore have now isolated the corresponding tests
> and marked them xfail.
> Second, in the comments on that PR some existing inconsistencies between the handling
> of ‘illegal’ exponents had been discussed; see my last comment for a kind of summary.
> Summary of the summary, strings with exponents exceeding float64 range are e.g. read
> in as inf and 0.0 in plain Python [float('1.423e388’)], while the ascii.io standard has generally
> asked to return such entries as string fields. Numpy OTOH can parse such numbers as
> extended precision if specifically asked:
> 
> np.float128('1.423e388')*10
> 1.423e+389
> 
> So I’d also like to poll if there is general interest in having ascii.io be able to handle such
> numbers as well (set by an option, if necessary), which might then include four-digit
> exponents.
> 
Thanks,
					Derek