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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def xche4_teff(self,ifig=None,lims=[1.,0.,3.4,4.7],label=None,colour=None, s2ms=True,dashes=None):
 """ Plot effective temperature against central helium abundance. Parameters ifig : integer or string Figure label, if None the current figure is used The default value is None. lims : list [x_lower, x_upper, y_lower, y_upper] label : string Label for the model The default value is None colour : string The colour of the line The default value is None s2ms : boolean, optional "Skip to Main Sequence" The default is True dashes : list, optional Custom dashing style. If None, ignore. The default is None. """

        fsize=18
        params = {'axes.labelsize':  fsize,
        #    'font.family':       'serif',
        'font.family':        'Times New Roman',
        'figure.facecolor':  'white',
        'text.fontsize':     fsize,
        'legend.fontsize':   fsize,
        'xtick.labelsize':   fsize*0.8,
        'ytick.labelsize':   fsize*0.8,
        'text.usetex':       False}

        try:
            pl.rcParams.update(params)
        except:
            pass


        if s2ms:
            h1=self.get('center_h1')
            idx=np.where(h1[0]-h1>=1.e-3)[0][0]
            skip=idx
        else:
            skip=0

        x = self.get('center_he4')[skip:]
        y = self.get('log_Teff')[skip:]
        if ifig is not None:
            pl.figure(ifig)
        if label is not None:
            if colour is not None:
                line,=pl.plot(x,y,label=label,color=colour)
            else:
                line,=pl.plot(x,y,label=label)
            pl.legend(loc='best').draw_frame(False)
        else:
            if colour is not None:
                line,=pl.plot(x,y,color=colour)
            else:
                line,=pl.plot(x,y)

        if dashes is not None:
            line.set_dashes(dashes)

        if label is not None:
            pl.legend(loc='best').draw_frame(False)

        pl.xlim(lims[:2])
        pl.ylim(lims[2:])
        pl.xlabel('$X_{\\rm c}(\,^4{\\rm He}\,)$')
        pl.ylabel('$\log\,T_{\\rm eff}$')