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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 from_analysis_period(cls, analysis_period=None):
 """Create and AnalysisPeriod from an analysis period. This method is useful to be called from inside Grasshopper or Dynamo """

        if not analysis_period:
            return cls()
        elif hasattr(analysis_period, 'isAnalysisPeriod'):
            return analysis_period
        elif isinstance(analysis_period, str):
            try:
                return cls.from_string(analysis_period)
            except Exception as e:
                raise ValueError(
                    "{} is not convertable to an AnalysisPeriod: {}".format(
                        analysis_period, e)
                )