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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def draw_lines():
 """ Draws a line between a set of random values """

    r = numpy.random.randn(200)
    fig = pyplot.figure()
    ax = fig.add_subplot(111)
    ax.plot(r)

    ax.grid(True)

    pyplot.savefig(lines_filename)