import PyGnuplot as Gp first = True base = 0 file = open("ground_readings_altered.csv", "r") x = [] y = [] for line in file.readlines(): elements = line.split(";") if first: base = int(elements[0]) first = False x.append((int(elements[0]) - base) / 1000000000) y.append(elements[1].replace(",", ".")) Gp.plot([x, y], "ground.dat")