branch.GetEntries("condition")

[vpadulan]

You can also directly print them via

import ROOT
df = ROOT.RDataFrame(“nominal”,“user.ehaaland.29804058._000001.minitrees.root”)
df.Display("systName", nRows=10).Print()

Change the nRows parameter if you want to print more rows

[Wile_E_Coyote]

Try (note: “_” or “__” before “1down”?):
print(df.Filter('systName.EqualTo("EG_SCALE_AF2__1down")').Count().GetValue())

[roy.brener]

Yes, that works, nice catch @Wile_E_Coyote! Sorry for the many iterations, I’ve copied from the first dF suggestion which had it as EG_SCALE_AF2_1down instead of EG_SCALE_AF2__1down which I’ve missed. Anyway we have two working solutions for that particular problem. Many many thanks @Wile_E_Coyote and @vpadulan for all your help and patience!