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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 games_behind(self):
 """ Returns a ``float`` of the number of games behind the leader the team is. 0.0 indicates the team is tied for first. Negative numbers indicate the number of games a team is ahead of the second place team. """

        if 'up' in self._games_behind.lower():
            games_behind = re.sub('up *', '', self._games_behind.lower())
            try:
                return float(games_behind) * -1.0
            except ValueError:
                return None
        if 'tied' in self._games_behind.lower():
            return 0.0
        try:
            return float(self._games_behind)
        except ValueError:
            return None