code: def filter_by_conditional_statement(self, statement):
          
          _filt_values, _filt_datetimes = self._filter_by_statement(statement)
          collection = HourlyDiscontinuousCollection(
              self.header.duplicate(), _filt_values, _filt_datetimes)
          collection._validated_a_period = True
          return collection
docs: Filter the Data Collection based on a conditional statement.
  
          Args:
              statement: A conditional statement as a string (e.g. a > 25 and a%5 == 0).
                  The variable should always be named as 'a' (without quotations).
  
          Return:
              A new Data Collection containing only the filtered data