This [script](https://osf.io/mrf5v) prints reaction timescales from data in a Webnucleo XML file. To use, first download the file by typing **curl -o reac_timescale.py -J -L https://osf.io/mrf5v/download** Use the script on an output Webnucleo XML file (in this example, called *out.xml*). This will be an output from a Webnucleo network calculation, but, to obtain an [example](https://osf.io/zhrfn/), type **curl -o out.xml -J -L https://osf.io/ytud2/download** Then print the reaction timescales from *out.xml* for reactions (in this example, the *(p, γ)* reaction on o16) in particular zones (in this example, all zones after and including zone 9 since the first zone is zone 0) by typing **python reac_timescale.py out.xml --reac_xpath "[reactant = 'h1' and reactant = 'o16' and product = 'gamma']" --zone_xpath "[position() >= 10]"** For each zone printed out, the output will be each reaction matched by the reaction XPath (if the flows are non-zero), the flows, and the timescale and net timescale for the given species to be destroyed by the reaction. A negative timescale means the reaction is tending to make the species.