Cut strings and looping over events

[Demosthene]

Hi, I’d like to extract a list of all the event numbers associated with entries that pass a given cut.
For, instance, setting up with

from ROOT import *
f = TFile.Open("myfile.root","r")
t = f.Get("mytree")
cut = "nJets>4 && pT_1jet>20 && nLeptons==0" #or whatever
saved = []

I can then get the total number of entries satisfying my cut with

t.GetEntries(cut)

or I can loop over the tree and extract some variables:

for entry in t:
    saved.append(entry.eventNumber)

Now, how do I get myvar only for events that pass cut? Surely there’s another way than manually writing:

for entry in t:
    if entry.nJets>4 and entry.pT_1jet>20 and entry.nLeptons==0:
        saved.append(entry.eventNumber)

Ideally I should be able to use this script with any arbitrarily long or complex cut string…

[Demosthene]

Apparently the following works:

elist = TEventList()
t.Draw(">>elist",cut)
for i in range(0,elist.GetN()):
    t.GetEntry(elist.GetEntry(i))
    saved.append(eventNumber)

Is that correct?