TaxBenefitSystem¶

class openfisca_core.taxbenefitsystems.TaxBenefitSystem(entities)[source]¶

Represents the legislation.

It stores parameters (values defined for everyone) and variables (values defined for some given entity e.g. a person).

parameters¶: Directory containing the YAML parameter files.

Parameters:: entities (Sequence[Entity]) – Entities used by the tax benefit system.

add_variable(variable)[source]¶

Adds an OpenFisca variable to the tax and benefit system.

Parameters:: variable (Variable) – The variable to add. Must be a subclass of Variable.
Raises:: openfisca_core.errors.VariableNameConflictError – if a variable with the same name have previously been added to the tax and benefit system.
Return type:: Variable

add_variables(*variables)[source]¶

Adds a list of OpenFisca Variables to the TaxBenefitSystem.

See also add_variable

Return type:: None

add_variables_from_directory(directory)[source]¶

Recursively explores a directory, and adds all OpenFisca variables found there to the tax and benefit system.

Return type:: None

add_variables_from_file(file_path)[source]¶

Adds all OpenFisca variables contained in a given file to the tax and benefit system.

Return type:: None

apply_reform(reform_path)[source]¶

Generates a new tax and benefit system applying a reform to the tax and benefit system.

The current tax and benefit system is not mutated.

Parameters:: reform_path (str) – The reform to apply. Must respect the format installed_package.sub_module.reform
Returns:: TaxBenefitSystem – A reformed tax and benefit system.
Return type:: TaxBenefitSystem

Example

>>> self.apply_reform("openfisca_france.reforms.inversion_revenus")

get_package_metadata()[source]¶

Gets metadata relative to the country package.

Returns:: A dictionary with the country package metadata
Return type:: dict[str, str]

Example

>>> tax_benefit_system.get_package_metadata()
>>> {
>>>    'location': '/path/to/dir/containing/package',
>>>    'name': 'openfisca-france',
>>>    'repository_url': 'https://github.com/openfisca/openfisca-france',
>>>    'version': '17.2.0'
>>>    }

get_parameters_at_instant(instant)[source]¶

Get the parameters of the legislation at a given instant.

Parameters:: instant (str | int | Period | Instant) – str formatted “YYYY-MM-DD” or Instant.
Returns:: The parameters of the legislation at a given instant.
Return type:: ParameterNodeAtInstant | None

get_variable(variable_name, check_existence=False)[source]¶

Get a variable from the tax and benefit system.

Parameters:

variable_name (str) – Name of the requested variable.
check_existence (bool) – If True, raise an error if the requested variable does not exist.

Return type:

Variable | None

get_variables(entity=None)[source]¶

Gets all variables contained in a tax and benefit system.

Parameters:: entity (Entity | None) – If set, returns the variable defined for the given entity.
Returns:: A dictionary, indexed by variable names.
Return type:: dict[str, Variable]

load_extension(extension)[source]¶

Loads an extension to the tax and benefit system.

Parameters:: extension (str) – The extension to load. Can be an absolute path pointing to an extension directory, or the name of an OpenFisca extension installed as a pip package.
Return type:: None

load_parameters(path_to_yaml_dir)[source]¶

Loads the legislation parameter for a directory containing YAML parameters files.

Parameters:: path_to_yaml_dir – Absolute path towards the YAML parameter directory.
Return type:: None

Example: >>> self.load_parameters(“/path/to/yaml/parameters/dir”)

neutralize_variable(variable_name)[source]¶

Neutralizes an OpenFisca variable existing in the tax and benefit system.

A neutralized variable always returns its default value when computed.

Trying to set inputs for a neutralized variable has no effect except raising a warning.

Return type:: None

replace_variable(variable)[source]¶

Replaces an existing variable by a new one.

The new variable must have the same name than the replaced one.

If no variable with the given name exists in the Tax-Benefit system, no error will be raised and the new variable will be simply added.

Parameters:: variable (Variable) – The variable to replace.
Return type:: None

update_variable(variable)[source]¶

Update an existing variable in the Tax-Benefit system.

All attributes of the updated variable that are not explicitly overridden by the new variable will stay unchanged.

The new variable must have the same name than the updated one.

If no variable with the given name exists in the tax and benefit system, no error will be raised and the new variable will be simply added.

Parameters:: variable (Variable) – Variable to add. Must be a subclass of Variable.
Returns:: The added variable.
Return type:: Variable