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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 resize_avatar(self, img, base_width):
 """Resize an avatar. :param img: The image that needs to be resize. :param base_width: The width of output image. """

        w_percent = (base_width / float(img.size[0]))
        h_size = int((float(img.size[1]) * float(w_percent)))
        img = img.resize((base_width, h_size), PIL.Image.ANTIALIAS)
        return img