Plotting Ratioplots for branches from multiple Root files

Hello All,
I am new to Root and python plotting. I am trying to plot histograms from multiple root files. Each Root file has tTree(Y) with one branch named X. I would like to plot the original histograms along with ratio plots (i.e. ratio of the branch (X) from all root files w.r.t branch (X) from first root file).
I have two questions:
1) I tried to copy an example from the ROOT forum (ROOT: tutorials/hist/ratioplot1.py File Reference) and run it using python3 on my bash. I do not see any output. What am I missing?
2) I tried to plot histograms and ratio plots myself. I want to put all ratio plots in a list and then call the list with for loop to draw all plots. However I am unable to set the legend size, titles, etc for my ratio plots after/under for the loop. Can somebody please help me to fix this?
Here is a snippet of my code

pad2 = ROOT.TPad("pad2", "pad2", 0, 0.05, 1, 0.3)
pad2.SetTopMargin(0)  # joins upper and lower plot
pad2.SetLeftMargin(0.15)
pad2.SetBottomMargin(0.2)
 # pad2.SetGridx()
pad2.Draw()  
pad2.cd()
ratio_plot_list=[R1,R2,R3,R4,R5]
for ratio_plot in ratio_plot_list:
    ratio_plot.SetTitle("")
    ratio_plot.SetStats(0)
    ratio_plot.SetMaximum(1.5)
    ratio_plot.SetMinimum(0.5)
    ratio_plot.GetYaxis().SetNdivisions(10)
    ratio_plot.GetYaxis().SetNdivisions(10)
    ratio_plot.GetYaxis().SetLabelSize(21) 
    ratio_plot.GetXaxis().SetTitleSize(21)
    ratio_plot.GetXaxis().SetTitleFont(42)
    ratio_plot.GetXaxis().SetTitleOffset(0.4)
    ratio_plot.Draw("hist""SAME") 
c.cd()
c.Draw()

Hi,
You need to make sure the histogram objects are not deleted and also the TRatioPlot is not deleted. You might need to clone the histogram before passing them to the TRatioPlot. @couet can help you also for your second question

Cheers

Lorenzo