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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 _fill(self):
 """Create the gradient."""

        r, g, b = hue2col(self._hue)
        width = self.winfo_width()
        height = self.winfo_height()
        h = float(height - 1)
        w = float(width - 1)
        if height:
            c = [(r + i / h * (255 - r), g + i / h * (255 - g), b + i / h * (255 - b)) for i in range(height)]
            data = []
            for i in range(height):
                line = []
                for j in range(width):
                    rij = round2(j / w * c[i][0])
                    gij = round2(j / w * c[i][1])
                    bij = round2(j / w * c[i][2])
                    color = rgb_to_hexa(rij, gij, bij)
                    line.append(color)
                data.append("{" + " ".join(line) + "}")
            self.bg.put(" ".join(data))