code: def set_input(self, variable_name, period, value):
          
          variable = self.tax_benefit_system.get_variable(variable_name, check_existence = True)
          period = periods.period(period)
          if ((variable.end is not None) and (period.start.date > variable.end)):
              return
          self.get_holder(variable_name).set_input(period, value)
docs: Set a variable's value for a given period
  
              :param variable: the variable to be set
              :param value: the input value for the variable
              :param period: the period for which the value is setted
  
              Example:
              >>> from openfisca_country_template import CountryTaxBenefitSystem
              >>> simulation = Simulation(CountryTaxBenefitSystem())
              >>> simulation.set_input('age', '2018-04', [12, 14])
              >>> simulation.get_array('age', '2018-04')
              array([12, 14], dtype=int32)
  
              If a ``set_input`` property has been set for the variable, this method may accept inputs for periods not matching the ``definition_period`` of the variable. To read more about this, check the `documentation <https://openfisca.org/doc/coding-the-legislation/35_periods.html#automatically-process-variable-inputs-defined-for-periods-not-matching-the-definitionperiod>`_.