from ROOT import TH1F, TRandom

rnd = TRandom()

h = TH1F("histo",";Data;Enries",50,-5,5)

for i in range(1,10000):
    r1 = rnd.Uniform(-2,2)
    r2 = rnd.Uniform(-2,2)
    r3 = r1 + r2
    h.Fill(r3)

h.Draw();

input("Press Enter to continue...")