#!/usr/bin/env python
# coding: utf-8

# # Access TTree in Python using PyROOT and fill a histogram

# In[1]:


from ROOTaaS.iPyROOT import ROOT


# Open a file which is located on the web. No type is to be specified for "f".

# In[2]:


f = ROOT.TFile.Open("https://indico.cern.ch/event/395198/material/0/0.root");


# Loop over the TTree called "events" in the file. It is accessed with the dot operator.
# Same holds for the access to the branches: no need to set them up - they are just accessed by name, again with the dot operator.

# In[3]:


h = ROOT.TH1F("TracksPt","Tracks;Pt [GeV/c];#",128,0,64)
for event in f.events:
    for track in event.tracks:
        h.Fill(track.Pt())
h.Draw()


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