How to use the astropy.io.fits.Column function in astropy

raise RuntimeError('Mismatch between length of FITS table ({0}) and length of phase array ({1})!'.format(len(hdulist[1].data),len(phases)))
        data_to_add = {'PULSE_PHASE':[phases,'D']}
        if args.absphase:
            data_to_add['ABS_PHASE'] = [iphss-negmask*u.cycle,'K']
        if args.barytime:
            tdbs = np.asarray([t.mjd for t in ts.table['tdb']])
            data_to_add['BARY_TIME'] = [tdbs,'D']
        for key in data_to_add.keys():
            if key in hdulist[1].columns.names:
                log.info('Found existing %s column, overwriting...'%key)
                # Overwrite values in existing Column
                hdulist[1].data[key] = data_to_add[key][0]
            else:
                # Construct and append new column, preserving HDU header and name
                log.info('Adding new %s column.'%key)
                datacol = pyfits.ColDefs([pyfits.Column(name=key,
                    format=data_to_add[key][1], array=data_to_add[key][0])])
                bt = pyfits.BinTableHDU.from_columns(
                    hdulist[1].columns + datacol, header=hdulist[1].header,
                    name=hdulist[1].name)
                hdulist[1] = bt
        if args.outfile is None:
            # Overwrite the existing file
            log.info('Overwriting existing FITS file '+args.eventfile)
            hdulist.flush(verbose=True, output_verify='warn')
        else:
            # Write to new output file
            log.info('Writing output FITS file '+args.outfile)
            hdulist.writeto(args.outfile,overwrite=True, checksum=True, output_verify='warn')

def simple_generic_writer(data, file_name, **kwargs):
    """
    Basic `Spectrum1DRef` FITS writer.
    """
    # Create fits columns
    flux_col = fits.Column(name='FLUX', format='E', array=data.data)
    disp_col = fits.Column(name='WAVE', format='E', array=data.dispersion)
    uncert_col = fits.Column(name='UNCERT', format='E', array=data.uncertainty.array)
    mask_col = fits.Column(name='MASK', format='L', array=data.mask)

    cols = fits.ColDefs([flux_col, disp_col, uncert_col, mask_col])

    # Create the bin table
    tbhdu = fits.BinTableHDU.from_columns(cols)

    # Create header
    prihdu = fits.PrimaryHDU(header=data.meta.get('header', data.wcs.to_header() if data.wcs is not None else None))

    # Compose
    thdulist = fits.HDUList([prihdu, tbhdu])
    thdulist.writeto("{}.fits".format(file_name), overwrite=True)

hdulist['AIPS AN'].header = head

    ##################### AIPS FQ TABLE #####################################################################################################
    # Convert types & columns
    freqid = np.array([1])
    bandfreq = np.array([ch1_freq + ch_spacing*i - ref_freq for i in range(nchan)]).reshape([1,nchan])
    chwidth = np.array([ch_bw for i in range(nchan)]).reshape([1,nchan])
    totbw = np.array([ch_bw for i in range(nchan)]).reshape([1,nchan])
    sideband = np.array([1 for i in range(nchan)]).reshape([1,nchan])

    freqid = fits.Column(name="FRQSEL", format="1J", array=freqid)
    bandfreq = fits.Column(name="IF FREQ", format="%dD"%(nchan), array=bandfreq, unit='HZ')
    chwidth = fits.Column(name="CH WIDTH",format="%dE"%(nchan), array=chwidth, unit='HZ')
    totbw = fits.Column(name="TOTAL BANDWIDTH",format="%dE"%(nchan),array=totbw, unit='HZ')
    sideband = fits.Column(name="SIDEBAND",format="%dJ"%(nchan),array=sideband)
    cols = fits.ColDefs([freqid, bandfreq, chwidth, totbw, sideband])

    # create table
    tbhdu = fits.BinTableHDU.from_columns(cols)

    # header information
    tbhdu.header.append(("NO_IF", nchan, "Number IFs"))
    tbhdu.header.append(("EXTNAME","AIPS FQ"))
    tbhdu.header.append(("EXTVER",1))
    hdulist.append(tbhdu)

    ##################### AIPS NX TABLE #####################################################################################################

    scan_times = []
    scan_time_ints = []
    start_vis = []

head['FREQID'] = 1

    hdulist['AIPS AN'].header = head

    ##################### AIPS FQ TABLE #####################################################################################################
    # Convert types & columns
    freqid = np.array([1])
    bandfreq = np.array([ch1_freq + ch_spacing*i - ref_freq for i in range(nchan)]).reshape([1,nchan])
    chwidth = np.array([ch_bw for i in range(nchan)]).reshape([1,nchan])
    totbw = np.array([ch_bw for i in range(nchan)]).reshape([1,nchan])
    sideband = np.array([1 for i in range(nchan)]).reshape([1,nchan])

    freqid = fits.Column(name="FRQSEL", format="1J", array=freqid)
    bandfreq = fits.Column(name="IF FREQ", format="%dD"%(nchan), array=bandfreq, unit='HZ')
    chwidth = fits.Column(name="CH WIDTH",format="%dE"%(nchan), array=chwidth, unit='HZ')
    totbw = fits.Column(name="TOTAL BANDWIDTH",format="%dE"%(nchan),array=totbw, unit='HZ')
    sideband = fits.Column(name="SIDEBAND",format="%dJ"%(nchan),array=sideband)
    cols = fits.ColDefs([freqid, bandfreq, chwidth, totbw, sideband])

    # create table
    tbhdu = fits.BinTableHDU.from_columns(cols)

    # header information
    tbhdu.header.append(("NO_IF", nchan, "Number IFs"))
    tbhdu.header.append(("EXTNAME","AIPS FQ"))
    tbhdu.header.append(("EXTVER",1))
    hdulist.append(tbhdu)

    ##################### AIPS NX TABLE #####################################################################################################

    scan_times = []
    scan_time_ints = []

if status == 0:
        col1 = pyfits.Column(name='TIME',format='D',unit='BJD - 2454833',array=time)
        col2 = pyfits.Column(name='TIMECORR',format='E',unit='d',array=timecorr)
        col3 = pyfits.Column(name='CADENCENO',format='J',array=cadenceno)
        col4 = pyfits.Column(name='SAP_FLUX',format='E',array=sap_flux)
        col5 = pyfits.Column(name='SAP_FLUX_ERR',format='E',array=sap_flux_err)
        col6 = pyfits.Column(name='SAP_BKG',format='E',array=sap_bkg)
        col7 = pyfits.Column(name='SAP_BKG_ERR',format='E',array=sap_bkg_err)
        col8 = pyfits.Column(name='PDCSAP_FLUX',format='E',array=sap_flux)
        col9 = pyfits.Column(name='PDCSAP_FLUX_ERR',format='E',array=sap_flux_err)
        col10 = pyfits.Column(name='SAP_QUALITY',format='J',array=quality)
        col11 = pyfits.Column(name='PSF_CENTR1',format='E',unit='pixel',array=psf_centr1)
        col12 = pyfits.Column(name='PSF_CENTR1_ERR',format='E',unit='pixel',array=psf_centr1_err)
        col13 = pyfits.Column(name='PSF_CENTR2',format='E',unit='pixel',array=psf_centr2)
        col14 = pyfits.Column(name='PSF_CENTR2_ERR',format='E',unit='pixel',array=psf_centr2_err)
        col15 = pyfits.Column(name='MOM_CENTR1',format='E',unit='pixel',array=mom_centr1)
        col16 = pyfits.Column(name='MOM_CENTR1_ERR',format='E',unit='pixel',array=mom_centr1_err)
        col17 = pyfits.Column(name='MOM_CENTR2',format='E',unit='pixel',array=mom_centr2)
        col18 = pyfits.Column(name='MOM_CENTR2_ERR',format='E',unit='pixel',array=mom_centr2_err)
        col19 = pyfits.Column(name='POS_CORR1',format='E',unit='pixel',array=pos_corr1)
        col20 = pyfits.Column(name='POS_CORR2',format='E',unit='pixel',array=pos_corr2)
        col21 = pyfits.Column(name='RAW_FLUX',format='E',array=raw_flux)
        cols = pyfits.ColDefs([col1,col2,col3,col4,col5,col6,col7,col8,col9,
                               col10,col11,col12,col13,col14,col15,col16,
                               col17,col18,col19,col20,col21])
        hdu1 = pyfits.BinTableHDU.from_columns(cols)
        hdu1.header['TTYPE1'] = ('TIME','column title: data time stamps')
        hdu1.header['TFORM1'] = ('D','data type: float64')
        hdu1.header['TUNIT1'] = ('BJD - 2454833','column units: barycenter corrected JD')
        hdu1.header['TDISP1'] = ('D12.7','column display format')
        hdu1.header['TTYPE2'] = ('TIMECORR','column title: barycentric-timeslice correction')
        hdu1.header['TFORM2'] = ('E','data type: float32')

poltya = np.full((self.Nants_telescope), 'X', dtype=np.object_)
        polaa = [90.0] + np.zeros(self.Nants_telescope)
        poltyb = np.full((self.Nants_telescope), 'Y', dtype=np.object_)
        polab = [0.0] + np.zeros(self.Nants_telescope)

        col1 = fits.Column(name='ANNAME', format='8A',
                           array=self.antenna_names)
        col2 = fits.Column(name='STABXYZ', format='3D',
                           array=self.antenna_positions)
        # convert to 1-indexed from 0-indexed indicies
        col3 = fits.Column(name='NOSTA', format='1J',
                           array=self.antenna_numbers + 1)
        col4 = fits.Column(name='MNTSTA', format='1J', array=mntsta)
        col5 = fits.Column(name='STAXOF', format='1E', array=staxof)
        col6 = fits.Column(name='POLTYA', format='1A', array=poltya)
        col7 = fits.Column(name='POLAA', format='1E', array=polaa)
        # col8 = fits.Column(name='POLCALA', format='3E', array=polcala)
        col9 = fits.Column(name='POLTYB', format='1A', array=poltyb)
        col10 = fits.Column(name='POLAB', format='1E', array=polab)
        # col11 = fits.Column(name='POLCALB', format='3E', array=polcalb)
        # note ORBPARM is technically required, but we didn't put it in

        cols = fits.ColDefs([col1, col2, col3, col4, col5, col6, col7, col9,
                             col10])

        ant_hdu = fits.BinTableHDU.from_columns(cols)

        ant_hdu.header['EXTNAME'] = 'AIPS AN'
        ant_hdu.header['EXTVER'] = 1

        # write XYZ coordinates if not already defined
        ant_hdu.header['ARRAYX'] = self.telescope_location[0]

format = 'E',
                                   array = numpy.insert(mag_err_array, 0, 0.))]
    hdu = pyfits.new_table(columns_array)
    hdu.name = 'BINS_MAG_ERR'
    hdul.append(hdu)

    # Store magnitude 1 info
    columns_array = [pyfits.Column(name = 'BINS_MAG_1',
                                   format = 'E',
                                   array = bins_mag_1)]
    hdu = pyfits.new_table(columns_array)
    hdu.name = 'BINS_MAG_1'
    hdul.append(hdu)

    # Store magnitude 2 info
    columns_array = [pyfits.Column(name = 'BINS_MAG_2',
                                   format = 'E',
                                   array = bins_mag_2)]
    hdu = pyfits.new_table(columns_array)
    hdu.name = 'BINS_MAG_2'
    hdul.append(hdu)

    logger.info('Writing look-up table to %s'%(outfile))
    hdul.writeto(outfile, clobber = True)

def _make_target_extension(self, ext_info):
        """Create the 'TARGETTABLES' extension (i.e. extension #1)."""
        # Turn the data arrays into fits columns and initialize the HDU
        coldim = '({},{})'.format(self.n_cols, self.n_rows)
        eformat = '{}E'.format(self.n_rows * self.n_cols)
        jformat = '{}J'.format(self.n_rows * self.n_cols)
        cols = []
        cols.append(fits.Column(name='TIME', format='D', unit='BJD - 2454833',
                                array=self.time))
        cols.append(fits.Column(name='TIMECORR', format='E', unit='D',
                                array=self.timecorr))
        cols.append(fits.Column(name='CADENCENO', format='J',
                                array=self.cadenceno))
        cols.append(fits.Column(name='RAW_CNTS', format=jformat,
                                unit='count', dim=coldim,
                                array=self.raw_cnts))
        cols.append(fits.Column(name='FLUX', format=eformat,
                                unit='e-/s', dim=coldim,
                                array=self.flux))
        cols.append(fits.Column(name='FLUX_ERR', format=eformat,
                                unit='e-/s', dim=coldim,
                                array=self.flux_err))
        cols.append(fits.Column(name='FLUX_BKG', format=eformat,
                                unit='e-/s', dim=coldim,
                                array=self.flux_bkg))
        cols.append(fits.Column(name='FLUX_BKG_ERR', format=eformat,
                                unit='e-/s', dim=coldim,
                                array=self.flux_bkg_err))

col7 = pyfits.Column(name='SAP_BKG_ERR', format='E', unit='e-/s',
                         array=sap_bkg_err)
    col8 = pyfits.Column(name='PDCSAP_FLUX', format='E', unit='e-/s',
                         array=pdc_flux)
    col9 = pyfits.Column(name='PDCSAP_FLUX_ERR', format='E', unit='e-/s',
                         array=pdc_flux_err)
    col10 = pyfits.Column(name='SAP_QUALITY', format='J', array=quality)
    col11 = pyfits.Column(name='PSF_CENTR1', format='E', unit='pixel',
                          array=psf_centr1)
    col12 = pyfits.Column(name='PSF_CENTR1_ERR', format='E', unit='pixel',
                          array=psf_centr1_err)
    col13 = pyfits.Column(name='PSF_CENTR2', format='E', unit='pixel',
                          array=psf_centr2)
    col14 = pyfits.Column(name='PSF_CENTR2_ERR', format='E', unit='pixel',
                          array=psf_centr2_err)
    col15 = pyfits.Column(name='MOM_CENTR1', format='E', unit='pixel',
                          array=mom_centr1)
    col16 = pyfits.Column(name='MOM_CENTR1_ERR', format='E', unit='pixel',
                          array=mom_centr1_err)
    col17 = pyfits.Column(name='MOM_CENTR2', format='E', unit='pixel',
                          array=mom_centr2)
    col18 = pyfits.Column(name='MOM_CENTR2_ERR', format='E', unit='pixel',
                          array=mom_centr2_err)
    col19 = pyfits.Column(name='POS_CORR1', format='E', unit='pixel',
                          array=pos_corr1)
    col20 = pyfits.Column(name='POS_CORR2', format='E', unit='pixel',
                          array=pos_corr2)
    col21 = pyfits.Column(name='PCA_FLUX', format='E', unit='e-/s',
                          array=fluxcor)
    col22 = pyfits.Column(name='PCA_FLUX_NRM', format='E', array=normfluxcor)
    cols = pyfits.ColDefs([col1, col2, col3, col4, col5, col6, col7, col8,
                           col9, col10, col11, col12, col13, col14, col15,

hdulist = pyfits.open(args.eventfile,mode='update')
        else:
            hdulist = pyfits.open(args.eventfile)
        event_hdu = hdulist[1]
        event_hdr=event_hdu.header
        event_dat=event_hdu.data
        if len(event_dat) != len(phases):
            raise RuntimeError('Mismatch between length of FITS table ({0}) and length of phase array ({1})!'.format(len(event_dat),len(phases)))
        if 'PULSE_PHASE' in event_hdu.columns.names:
            log.info('Found existing PULSE_PHASE column, overwriting...')
            # Overwrite values in existing Column
            event_dat['PULSE_PHASE'] = phases
        else:
            # Construct and append new column, preserving HDU header and name
            log.info('Adding new PULSE_PHASE column.')
            phasecol = pyfits.ColDefs([pyfits.Column(name='PULSE_PHASE', format='D',
                array=phases)])
            bt = pyfits.BinTableHDU.from_columns( event_hdu.columns + phasecol,
                header=event_hdr,name=event_hdu.name)
            hdulist[1] = bt
        if args.outfile is None:
            # Overwrite the existing file
            log.info('Overwriting existing FITS file '+args.eventfile)
            hdulist.flush(verbose=True, output_verify='warn')
        else:
            # Write to new output file
            log.info('Writing output FITS file '+args.outfile)
            hdulist.writeto(args.outfile,overwrite=True, checksum=True, output_verify='warn')

    return 0