How to use the lmfit.printfuncs.gformat function in lmfit

pname = param.name
            try:
                val = gformat(param.value)
            except (TypeError, ValueError):
                val = ' ??? '

            serr = ' N/A '
            if param.stderr is not None:
                serr = gformat(param.stderr, 10)
            extra = ' '
            if param.expr is not None:
                extra = ' = %s ' % param.expr
            elif not param.vary:
                extra = ' (fixed)'
            elif param.init_value is not None:
                extra = ' (init=%s)' % gformat(param.init_value, 11)

            wids['params'].AppendItem((pname, val, serr, extra))
            wids['paramsdata'].append(pname)
        self.Refresh()

self.owids['data_title'].SetLabel("%s:  %.3f sec" % (self.mca.label, result.count_time))
        self.owids['data_title2'].SetLabel("%s:  %.3f sec" % (self.mca.label, result.count_time))
        self.result = result
        self.owids['fitlabel_txt'].SetValue(result.label)
        self.owids['params'].DeleteAllItems()
        self.owids['paramsdata'] = []
        for param in reversed(result.params.values()):
            pname = param.name
            try:
                val = gformat(param.value, 10)
            except (TypeError, ValueError):
                val = ' ??? '

            serr, perr = ' N/A ', ' N/A '
            if param.stderr is not None:
                serr = gformat(param.stderr, 10)
                try:
                    perr = ' {:.2%}'.format(abs(param.stderr/param.value))
                except ZeroDivisionError:
                    perr = '?'
            extra = ' '
            if param.expr is not None:
                extra = ' = %s ' % param.expr
            elif not param.vary:
                extra = ' (fixed)'
            elif param.init_value is not None:
                extra = gformat(param.init_value, 10)

            self.owids['params'].AppendItem((pname, val, serr, perr, extra))
            self.owids['paramsdata'].append(pname)
        self.Refresh()

desc = desc[tlen+i:]
        parts.append(desc)
        wids['model_desc'].SetLabel('\n'.join(parts))

        wids['params'].DeleteAllItems()
        wids['paramsdata'] = []
        for param in reversed(result.params.values()):
            pname = param.name
            try:
                val = gformat(param.value)
            except (TypeError, ValueError):
                val = ' ??? '

            serr = ' N/A '
            if param.stderr is not None:
                serr = gformat(param.stderr, 10)
            extra = ' '
            if param.expr is not None:
                extra = ' = %s ' % param.expr
            elif not param.vary:
                extra = ' (fixed)'
            elif param.init_value is not None:
                extra = ' (init=%s)' % gformat(param.init_value, 11)

            wids['params'].AppendItem((pname, val, serr, extra))
            wids['paramsdata'].append(pname)
        self.Refresh()

def show_fitresult(self, nfit=0, mca=None):
        if mca is not None:
            self.mca = mca
        result = self.get_fitresult(nfit=nfit)

        self.owids['data_title'].SetLabel("%s:  %.3f sec" % (self.mca.label, result.count_time))
        self.owids['data_title2'].SetLabel("%s:  %.3f sec" % (self.mca.label, result.count_time))
        self.result = result
        self.owids['fitlabel_txt'].SetValue(result.label)
        self.owids['params'].DeleteAllItems()
        self.owids['paramsdata'] = []
        for param in reversed(result.params.values()):
            pname = param.name
            try:
                val = gformat(param.value, 10)
            except (TypeError, ValueError):
                val = ' ??? '

            serr, perr = ' N/A ', ' N/A '
            if param.stderr is not None:
                serr = gformat(param.stderr, 10)
                try:
                    perr = ' {:.2%}'.format(abs(param.stderr/param.value))
                except ZeroDivisionError:
                    perr = '?'
            extra = ' '
            if param.expr is not None:
                extra = ' = %s ' % param.expr
            elif not param.vary:
                extra = ' (fixed)'
            elif param.init_value is not None:

def show_results(self):
        cur = self.get_fitresult()
        wids = self.wids
        wids['stats'].DeleteAllItems()
        for i, res in enumerate(self.peakfit_history):
            args = ['%2.2d' % (i+1)]
            for attr in ('ndata', 'nvarys', 'nfev', 'chisqr', 'redchi', 'aic', 'bic'):
                val = getattr(res.result, attr)
                if isinstance(val, int):
                    val = '%d' % val
                else:
                    val = gformat(val, 11)
                args.append(val)
            wids['stats'].AppendItem(tuple(args))
        wids['data_title'].SetLabel(self.datagroup.filename)
        self.show_fitresult(nfit=0)

return

    topline = '=================== FEFFIT RESULTS ===================='
    header = '[[%s]]'
    varformat  = '   %12s = %s +/-%s   (init= %s)'
    fixformat  = '   %12s = %s (fixed)'
    exprformat = '   %12s = %s +/-%s  = \'%s\''
    out = [topline, header % 'Statistics']

    out.append('   nvarys, npts       =  %i, %i' % (result.nvarys,
                                                   result.ndata))
    out.append('   n_independent      =  %.3f'  % (result.n_independent))
    out.append('   chi_square         = %s'  % gformat(result.chi_square))
    out.append('   reduced chi_square = %s'  % gformat(result.chi_reduced))
    out.append('   r-factor           = %s'  % gformat(result.rfactor))
    out.append('   Akaike info crit   = %s'  % gformat(result.aic))
    out.append('   Bayesian info crit = %s'  % gformat(result.bic))
    out.append(' ')

    if len(datasets) == 1:
        out.append(header % 'Data')
    else:
        out.append(header % 'Datasets (%i)' % len(datasets))
    for i, ds in enumerate(datasets):
        tr = ds.transform
        if len(datasets) > 1:
            out.append(' dataset %i:' % (i+1))
        if isinstance(tr.kweight, Iterable):
            if isinstance(ds.epsilon_k[0], np.ndarray):
                msg = []
                for eps in ds.epsilon_k:
                    msg.append('Array(mean=%s, std=%s)' % (gformat(eps.mean()).strip(),

val = ' ??? '

            serr, perr = ' N/A ', ' N/A '
            if param.stderr is not None:
                serr = gformat(param.stderr, 10)
                try:
                    perr = ' {:.2%}'.format(abs(param.stderr/param.value))
                except ZeroDivisionError:
                    perr = '?'
            extra = ' '
            if param.expr is not None:
                extra = ' = %s ' % param.expr
            elif not param.vary:
                extra = ' (fixed)'
            elif param.init_value is not None:
                extra = gformat(param.init_value, 10)

            self.owids['params'].AppendItem((pname, val, serr, perr, extra))
            self.owids['paramsdata'].append(pname)
        self.Refresh()

# wids['show_e0'].SetValue(form['show_e0'])
        wids['show_fitrange'].SetValue(form['show_fitrange'])

        wids['stats'].DeleteAllItems()
        results = self.datagroup.lcf_result[:20]
        self.nresults = len(results)
        wids['nfits_title'].SetLabel('showing %i best results' % self.nresults)

        for i, res in enumerate(results):
            args = ['%2.2d' % (i+1)]
            for attr in ('nvarys', 'nfev', 'chisqr', 'redchi', 'aic', 'bic'):
                val = getattr(res.result, attr)
                if isinstance(val, int):
                    val = '%d' % val
                else:
                    val = gformat(val, 12)
                args.append(val)
            wids['stats'].AppendItem(tuple(args))

        wpan = self.wids['weightspanel']
        wpan.DestroyChildren()

        wview = self.wids['weights'] = dv.DataViewListCtrl(wpan, style=DVSTYLE)
        wview.Bind(dv.EVT_DATAVIEW_SELECTION_CHANGED, self.onSelectFitParam)
        wview.AppendTextColumn(' Fit #', width=50)

        for i, cname in enumerate(form['comp_names']):
            wview.AppendTextColumn(cname, width=100)
        wview.AppendTextColumn('Total', width=100)

        for col in range(len(form['comp_names'])+2):
            this = wview.Columns[col]