Writing a FITS file should not warn when clobber is set to True

[anntzer]

Currently, a user warning ("Overwriting existing file ...") is raised in astropy.io.fits.file, and in astropy.io.fits.hdu.table when writing a FITS file would overwrite an existing file. But such an overwrite can happen only if the user explicitly passed clobber=True to the writing function; moreover the warning is too late anyways as the file is going to be overwritten (... except if the user can Ctrl-C very quickly).
I know warnings can be silenced but I don't think this situation actually warrants a warning.

[astrofrog]

I agree, I always find it strange that the warning is emitted when clobber is explicitly set.

[taldcroft]

👍

[pllim]

👍

[embray]

Note: This is a duplicate of spacetelescope/PyFITS#43 so when it's fixed there the fix will be backported to Astropy.

When the issue first came up I asked around about it a bit and the general consensus seems to be in favor of this change (I wouldn't ask at all except that this behavior has been in PyFITS going back many years!)

[embray]

I should add: The original motivation for this is reasonable: PyFITS is very often used in applications, and in this case the user of that application or other third-party library may not be aware that the developer of that application wrote clobber=True, and so it's helpful to inform the user that this is happening. That said I would agree that this is the applications' job and not the library's.

[pchanial]

👍

[anntzer]

Any news on that? The patch in itself is quite simple (just remove a call to warn)... Would a PR help?

[embray]

A PR would always help. I agree with this issue but it's pretty low priority for me.

[embray]

Fixed by #2786.