I have got a wield result when I loop in TChain with pyROOT: only a few events are actually looped even the total number of events is more than a hundred! The related codes are as following
ch = root.TChain("events") ch.Add('rootfiles/*.root') for entry in ch: print entry.run
- The ch.GetEntries() give correct number of events
- If I use “hadd” to merge all root files into one before add to the chain, the result will be correct
- Using C++ code of TChain with the same method and same root files will provide correct results
Any idea of what happens?
ROOT Version: 5.34
Platform: CentOS Linux 7