def _open(file,mode='copyonwrite'):
    """Opens a FITS format file and calls _open_fix if header doesn't
    verify correctly.
    """
    import pyfits

    try:
        infits=pyfits.open(file,mode)   
        hdu=infits
    except (ValueError,pyfits.VerifyError,pyfits.FITS_SevereError):
        import sys
        #### I really only know how to deal with one error right now.
        #if str(sys.exc_info()[1])=='mandatory keywords are not fixed format':
        hdu=_open_fix(file)
        #else:
        #    print sys.exc_info()[1]
        #    print " Failed trying to repair  ", file
        #    raise
    
    for f in hdu:
        strip_pad(f)
    return hdu
Opens a FITS format file and calls _open_fix if header doesn't
    verify correctly.