docs: def get_flipped_ext(file_id,ccd):
      """Given a list of exposure numbers and CCD, get them from the DB"""
      
      import MOPfits
      import os, shutil
      
      filename=MOPfits.adGet(file_id,extno=int(ccd))
      if int(ccd)<18:
          tfname=filename+"F"
  	shutil.move(filename, tfname)
          os.system("imcopy %s[-*,-*] %s" % (tfname, filename))
  	os.unlink(tfname)
      if not os.access(filename,os.R_OK):
          return(None)
      return(filename)