How to use the drizzlepac.astrodrizzle function in drizzlepac

wht = 1./im['ERR'].data**2
        wht[(im['ERR'].data == 0) | (dq > 0) | (~np.isfinite(wht))] = 0
        wht[im['SCI'].data < -3*im['ERR'].data] = 0

        wht = np.cast[np.float32](wht)

        exp_wcs = pywcs.WCS(im[1].header, relax=True)
        exp_wcs.pscale = utils.get_wcs_pscale(exp_wcs)

        #pf = 0.5
        # import drizzlepac.wcs_functions as dwcs
        # xx = out_wcs.deepcopy()
        # #xx.all_pix2world = xx.wcs_world2pix
        # map = dwcs.WCSMap(exp_wcs, xx)

        astrodrizzle.adrizzle.do_driz(im['SCI'].data, exp_wcs, wht,
                                      inter_wcs, outsci, outwht, outctx,
                                      1., 'cps', 1,
                                      wcslin_pscale=exp_wcs.pscale,
                                      uniqid=1,
                                      pixfrac=pixfrac, kernel=kernel,
                                      fillval=0, stepsize=10,
                                      wcsmap=SIP_WCSMap)

        if ds9 is not None:
            ds9.view(outsci, header=outh)

    #outsci /= out_wcs.pscale**2
    rms = 1/np.sqrt(outwht)
    mask = (outwht == 0) | (rms > 100)
    rms[mask] = 0
    outsci[mask] = 0.

flt_wcs, 1, coeffs=True, interp='nearest',
                                sinscl=1.0, stepsize=1, wcsmap=None)
            
            blotted_ones = astrodrizzle.ablot.do_blot(seg_ones+1, ref_wcs,
                                flt_wcs, 1, coeffs=True, interp='nearest',
                                sinscl=1.0, stepsize=1, wcsmap=None)
            
            blotted_ones[blotted_ones == 0] = 1
            ratio = np.round(blotted_seg/blotted_ones)
            grow = nd.maximum_filter(ratio, size=3, mode='constant', cval=0)
            ratio[ratio == 0] = grow[ratio == 0]
            blotted = ratio
            
        else:
            #print '\nREFDATA\n\n', refdata.dtype, ref_wcs, flt_wcs
            blotted = astrodrizzle.ablot.do_blot(refdata, ref_wcs, flt_wcs, 1, coeffs=True, interp='poly5', sinscl=1.0, stepsize=10, wcsmap=None)
        
        return blotted