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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 _update_alpha(self, event=None):
 """Update display after a change in the alpha spinbox."""

        a = self.alpha.get()
        hexa = self.hexa.get()
        hexa = hexa[:7] + ("%2.2x" % a).upper()
        self.hexa.delete(0, 'end')
        self.hexa.insert(0, hexa)
        self.alphabar.set(a)
        self._update_preview()