import ROOT
import sys

if len(sys.argv) == 2 and sys.argv[1] == "read":
    tf = ROOT.TFile("test.root")
    obj = tf.Get("object")
    tf.Close()
else:
    tf = ROOT.TFile("test.root", "RECREATE")
    obj = ROOT.TF1("myfunc", "[0]*exp(-[1]*x)+[2]+[3]*x", 0, 10)
    obj.SetParameters(1.12147e-01, 3.81701e+00, 0.0093, -6.14984e-04)
    obj.Write("object")
    tf.Close()