[AstroPy] Equivalent expression for SXPAR from IDL in python

Roberts, Michael michael.roberts.15 at ucl.ac.uk
Sun Feb 14 07:47:59 EST 2016

I'm hoping this question is relatively straightforward for those proficient with IDL and python and fits file handling (I'm using the astropy.fits module)

I'm looking to find an equivalent to SXPAR (whose function is to obtain the value of a parameter in a FITS header) from IDL into python...


"sxpar.pro" - idlastro.gsfc.nasa.gov<http://idlastro.gsfc.nasa.gov/ftp/pro/fits/sxpar.pro>
Apostrophes are stripped ; from strings. If the parameter is logical, 1b is ; returned for T, and 0b is returned for F. ; If Name was of ...

This is the original code in IDL:

nxpix_uw1_ext1 = sxpar(hima_sk_uw1_ext1,'NAXIS1')

nypix_uw1_ext1 = sxpar(hima_sk_uw1_ext1,'NAXIS2')

This is my conversion attempt into python using astropy.fits:

from astropy.io import fits

hima_sk_um2 = fits.open('') #Will contain the directory extension to the fits/img file I wish to open

# Compute the size of the images (you can also do this manually rather than calling these keywords from the header):

nxpix_um2_ext1 = hima_sk_um2[1].header['NAXIS1']

nypix_um2_ext1 = hima_sk_um2[1].header['NAXIS2']

Firstly, is this correct? And secondly, is this the best way to handle an extension value?

Any advise would be warmly received.

Many thanks,

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20160214/1b85e429/attachment.html>

More information about the AstroPy mailing list