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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 postcmd(self):
 """Make sure proper entry is activated when menu is posted"""

        value = self.choice.get()
        try:
            index = self.paramInfo.choice.index(value)
            self.entry.menu.activate(index)
        except ValueError:
            # initial null value may not be in list
            pass