code: def header_odict(nside,nest=False,coord=None, partial=True):
      
      hdr = odict([])
      hdr['PIXTYPE']=odict([('name','PIXTYPE'),
                            ('value','HEALPIX'),
                            ('comment','HEALPIX pixelisation')])
  
      ordering = 'NEST' if nest else 'RING'
      hdr['ORDERING']=odict([('name','ORDERING'),
                             ('value',ordering),
                             ('comment','Pixel ordering scheme, either RING or NESTED')])
      hdr['NSIDE']=odict([('name','NSIDE'),
                          ('value',nside),
                          ('comment','Resolution parameter of HEALPIX')])
      if coord:
          hdr['COORDSYS']=odict([('name','COORDSYS'), 
                                 ('value',coord), 
                                 ('comment','Ecliptic, Galactic or Celestial (equatorial)')])
      
      if not partial:
          hdr['FIRSTPIX']=odict([('name','FIRSTPIX'),
                                 ('value',0), 
                                 ('comment','First pixel # (0 based)')])
          hdr['LASTPIX']=odict([('name','LASTPIX'),
                                ('value',hp.nside2npix(nside)-1),
                                ('comment','Last pixel # (0 based)')])
      hdr['INDXSCHM']=odict([('name','INDXSCHM'),
                             ('value','EXPLICIT' if partial else 'IMPLICIT'),
                             ('comment','Indexing: IMPLICIT or EXPLICIT')])
      hdr['OBJECT']=odict([('name','OBJECT'), 
                           ('value','PARTIAL' if partial else 'FULLSKY'),
                           ('comment','Sky coverage, either FULLSKY or PARTIAL')])
      return hdr
docs: Mimic the healpy header keywords.