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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 image_scale(xscale=1.0, yscale=1.0, axes="gca"):
 """ Scales the image extent. """

    if axes == "gca": axes = _pylab.gca()

    e = axes.images[0].get_extent()
    x1 = e[0]*xscale
    x2 = e[1]*xscale
    y1 = e[2]*yscale
    y2 = e[3]*yscale

    image_set_extent([x1,x2],[y1,y2], axes)