Source code for openfisca_core.taxbenefitsystems.tax_benefit_system

from __future__ import annotations

from typing import Any, Dict, Optional, Sequence

import copy
import glob
import importlib
import inspect
import logging
import os
import pkg_resources
import sys
import traceback
import typing

from openfisca_core import commons, periods, variables
from openfisca_core.entities import Entity
from openfisca_core.errors import VariableNameConflictError, VariableNotFoundError
from openfisca_core.parameters import ParameterNode
from openfisca_core.periods import Instant, Period
from openfisca_core.populations import Population, GroupPopulation
from openfisca_core.simulations import SimulationBuilder
from openfisca_core.variables import Variable

log = logging.getLogger(__name__)


[docs]class TaxBenefitSystem: """ Represents the legislation. It stores parameters (values defined for everyone) and variables (values defined for some given entity e.g. a person). Attributes: parameters: Directory containing the YAML parameter files. Args: entities: Entities used by the tax benefit system. """ _base_tax_benefit_system = None _parameters_at_instant_cache: Optional[Dict[Any, Any]] = None person_key_plural = None preprocess_parameters = None baseline = None # Baseline tax-benefit system. Used only by reforms. Note: Reforms can be chained. cache_blacklist = None decomposition_file_path = None def __init__(self, entities: Sequence[Entity]) -> None: # TODO: Currently: Don't use a weakref, because they are cleared by Paste (at least) at each call. self.parameters: Optional[ParameterNode] = None self._parameters_at_instant_cache = {} # weakref.WeakValueDictionary() self.variables: Dict[Any, Any] = {} self.open_api_config: Dict[Any, Any] = {} # Tax benefit systems are mutable, so entities (which need to know about our variables) can't be shared among them if entities is None or len(entities) == 0: raise Exception("A tax and benefit sytem must have at least an entity.") self.entities = [copy.copy(entity) for entity in entities] self.person_entity = [entity for entity in self.entities if entity.is_person][0] self.group_entities = [entity for entity in self.entities if not entity.is_person] for entity in self.entities: entity.set_tax_benefit_system(self) @property def base_tax_benefit_system(self): base_tax_benefit_system = self._base_tax_benefit_system if base_tax_benefit_system is None: baseline = self.baseline if baseline is None: return self self._base_tax_benefit_system = base_tax_benefit_system = baseline.base_tax_benefit_system return base_tax_benefit_system def instantiate_entities(self): person = self.person_entity members = Population(person) entities: typing.Dict[Entity.key, Entity] = {person.key: members} for entity in self.group_entities: entities[entity.key] = GroupPopulation(entity, members) return entities # Deprecated method of constructing simulations, to be phased out in favor of SimulationBuilder def new_scenario(self): class ScenarioAdapter(object): def __init__(self, tax_benefit_system): self.tax_benefit_system = tax_benefit_system def init_from_attributes(self, **attributes): self.attributes = attributes return self def init_from_dict(self, dict): self.attributes = None self.dict = dict self.period = dict.pop('period') return self def new_simulation(self, debug = False, opt_out_cache = False, use_baseline = False, trace = False): # Legacy from scenarios, used in reforms tax_benefit_system = self.tax_benefit_system if use_baseline: while True: baseline = tax_benefit_system.baseline if baseline is None: break tax_benefit_system = baseline builder = SimulationBuilder() if self.attributes: variables = self.attributes.get('input_variables') or {} period = self.attributes.get('period') builder.set_default_period(period) simulation = builder.build_from_variables(tax_benefit_system, variables) else: builder.set_default_period(self.period) simulation = builder.build_from_entities(tax_benefit_system, self.dict) simulation.trace = trace simulation.debug = debug simulation.opt_out_cache = opt_out_cache return simulation return ScenarioAdapter(self) def prefill_cache(self): pass def load_variable(self, variable_class, update = False): name = variable_class.__name__ # Check if a Variable with the same name is already registered. baseline_variable = self.get_variable(name) if baseline_variable and not update: raise VariableNameConflictError( 'Variable "{}" is already defined. Use `update_variable` to replace it.'.format(name)) variable = variable_class(baseline_variable = baseline_variable) self.variables[variable.name] = variable return variable
[docs] def add_variable(self, variable: Variable) -> Variable: """Adds an OpenFisca variable to the tax and benefit system. Args: 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 self.load_variable(variable, update = False)
[docs] def replace_variable(self, variable): """ Replaces an existing OpenFisca variable in the tax and benefit system 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 and benefit system, no error will be raised and the new variable will be simply added. :param Variable variable: New variable to add. Must be a subclass of Variable. """ name = variable.__name__ if self.variables.get(name) is not None: del self.variables[name] self.load_variable(variable, update = False)
[docs] def update_variable(self, variable): """ Updates an existing OpenFisca variable in the tax and benefit system. All attributes of the updated variable that are not explicitely 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. :param Variable variable: Variable to add. Must be a subclass of Variable. """ return self.load_variable(variable, update = True)
[docs] def add_variables_from_file(self, file_path): """ Adds all OpenFisca variables contained in a given file to the tax and benefit system. """ try: file_name = os.path.splitext(os.path.basename(file_path))[0] # As Python remembers loaded modules by name, in order to prevent collisions, we need to make sure that: # - Files with the same name, but located in different directories, have a different module names. Hence the file path hash in the module name. # - The same file, loaded by different tax and benefit systems, has distinct module names. Hence the `id(self)` in the module name. module_name = f"{id(self)}_{hash(os.path.abspath(file_path))}_{file_name}" try: spec = importlib.util.spec_from_file_location(module_name, file_path) module = importlib.util.module_from_spec(spec) sys.modules[module_name] = module spec.loader.exec_module(module) except NameError as e: logging.error(str(e) + ": if this code used to work, this error might be due to a major change in OpenFisca-Core. Checkout the changelog to learn more: <https://github.com/openfisca/openfisca-core/blob/master/CHANGELOG.md>") raise potential_variables = [getattr(module, item) for item in dir(module) if not item.startswith('__')] for pot_variable in potential_variables: # We only want to get the module classes defined in this module (not imported) if inspect.isclass(pot_variable) and issubclass(pot_variable, Variable) and pot_variable.__module__ == module_name: self.add_variable(pot_variable) except Exception: log.error('Unable to load OpenFisca variables from file "{}"'.format(file_path)) raise
[docs] def add_variables_from_directory(self, directory): """ Recursively explores a directory, and adds all OpenFisca variables found there to the tax and benefit system. """ py_files = glob.glob(os.path.join(directory, "*.py")) for py_file in py_files: self.add_variables_from_file(py_file) subdirectories = glob.glob(os.path.join(directory, "*/")) for subdirectory in subdirectories: self.add_variables_from_directory(subdirectory)
[docs] def add_variables(self, *variables): """ Adds a list of OpenFisca Variables to the `TaxBenefitSystem`. See also :any:`add_variable` """ for variable in variables: self.add_variable(variable)
[docs] def load_extension(self, extension): """ Loads an extension to the tax and benefit system. :param str extension: 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. """ # Load extension from installed pip package try: package = importlib.import_module(extension) extension_directory = package.__path__[0] except ImportError: message = os.linesep.join([traceback.format_exc(), 'Error loading extension: `{}` is neither a directory, nor a package.'.format(extension), 'Are you sure it is installed in your environment? If so, look at the stack trace above to determine the origin of this error.', 'See more at <https://github.com/openfisca/openfisca-extension-template#installing>.']) raise ValueError(message) self.add_variables_from_directory(extension_directory) param_dir = os.path.join(extension_directory, 'parameters') if os.path.isdir(param_dir): extension_parameters = ParameterNode(directory_path = param_dir) self.parameters.merge(extension_parameters)
[docs] def apply_reform(self, reform_path: str) -> "TaxBenefitSystem": """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. Args: reform_path: The reform to apply. Must respect the format *installed_package.sub_module.reform* Returns: TaxBenefitSystem: A reformed tax and benefit system. Example: >>> self.apply_reform('openfisca_france.reforms.inversion_revenus') """ from openfisca_core.reforms import Reform try: reform_package, reform_name = reform_path.rsplit('.', 1) except ValueError: raise ValueError('`{}` does not seem to be a path pointing to a reform. A path looks like `some_country_package.reforms.some_reform.`'.format(reform_path)) try: reform_module = importlib.import_module(reform_package) except ImportError: message = os.linesep.join([traceback.format_exc(), 'Could not import `{}`.'.format(reform_package), 'Are you sure of this reform module name? If so, look at the stack trace above to determine the origin of this error.']) raise ValueError(message) reform = getattr(reform_module, reform_name, None) if reform is None: raise ValueError('{} has no attribute {}'.format(reform_package, reform_name)) if not issubclass(reform, Reform): raise ValueError('`{}` does not seem to be a valid Openfisca reform.'.format(reform_path)) return reform(self)
[docs] def get_variable(self, variable_name, check_existence = False): """ Get a variable from the tax and benefit system. :param variable_name: Name of the requested variable. :param check_existence: If True, raise an error if the requested variable does not exist. """ variables = self.variables found = variables.get(variable_name) if not found and check_existence: raise VariableNotFoundError(variable_name, self) return found
[docs] def neutralize_variable(self, variable_name): """ 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. """ self.variables[variable_name] = variables.get_neutralized_variable(self.get_variable(variable_name))
def annualize_variable(self, variable_name: str, period: typing.Optional[Period] = None): self.variables[variable_name] = variables.get_annualized_variable(self.get_variable(variable_name, period))
[docs] def load_parameters(self, path_to_yaml_dir): """ Loads the legislation parameter for a directory containing YAML parameters files. :param path_to_yaml_dir: Absolute path towards the YAML parameter directory. Example: >>> self.load_parameters('/path/to/yaml/parameters/dir') """ parameters = ParameterNode('', directory_path = path_to_yaml_dir) if self.preprocess_parameters is not None: parameters = self.preprocess_parameters(parameters) self.parameters = parameters
def _get_baseline_parameters_at_instant(self, instant): baseline = self.baseline if baseline is None: return self.get_parameters_at_instant(instant) return baseline._get_baseline_parameters_at_instant(instant)
[docs] def get_parameters_at_instant(self, instant): """ Get the parameters of the legislation at a given instant :param instant: :obj:`str` of the format 'YYYY-MM-DD' or :class:`.Instant` instance. :returns: The parameters of the legislation at a given instant. :rtype: :class:`.ParameterNodeAtInstant` """ if isinstance(instant, Period): instant = instant.start elif isinstance(instant, (str, int)): instant = periods.instant(instant) else: assert isinstance(instant, Instant), "Expected an Instant (e.g. Instant((2017, 1, 1)) ). Got: {}.".format(instant) parameters_at_instant = self._parameters_at_instant_cache.get(instant) if parameters_at_instant is None and self.parameters is not None: parameters_at_instant = self.parameters.get_at_instant(str(instant)) self._parameters_at_instant_cache[instant] = parameters_at_instant return parameters_at_instant
[docs] def get_package_metadata(self): """ Gets metatada relative to the country package the tax and benefit system is built from. :returns: Country package metadata :rtype: dict 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' >>> } """ # Handle reforms if self.baseline: return self.baseline.get_package_metadata() fallback_metadata = { 'name': self.__class__.__name__, 'version': '', 'repository_url': '', 'location': '', } module = inspect.getmodule(self) if not module.__package__: return fallback_metadata package_name = module.__package__.split('.')[0] try: distribution = pkg_resources.get_distribution(package_name) except pkg_resources.DistributionNotFound: return fallback_metadata location = inspect.getsourcefile(module).split(package_name)[0].rstrip('/') home_page_metadatas = [ metadata.split(':', 1)[1].strip(' ') for metadata in distribution._get_metadata(distribution.PKG_INFO) if 'Home-page' in metadata ] repository_url = home_page_metadatas[0] if home_page_metadatas else '' return { 'name': distribution.key, 'version': distribution.version, 'repository_url': repository_url, 'location': location, }
[docs] def get_variables(self, entity = None): """ Gets all variables contained in a tax and benefit system. :param Entity entity: If set, returns only the variable defined for the given entity. :returns: A dictionary, indexed by variable names. :rtype: dict """ if not entity: return self.variables else: return { variable_name: variable for variable_name, variable in self.variables.items() # TODO - because entities are copied (see constructor) they can't be compared if variable.entity.key == entity.key }
def clone(self): new = commons.empty_clone(self) new_dict = new.__dict__ for key, value in self.__dict__.items(): if key not in ('parameters', '_parameters_at_instant_cache', 'variables', 'open_api_config'): new_dict[key] = value for entity in new_dict['entities']: entity.set_tax_benefit_system(new) new_dict['parameters'] = self.parameters.clone() new_dict['_parameters_at_instant_cache'] = {} new_dict['variables'] = self.variables.copy() new_dict['open_api_config'] = self.open_api_config.copy() return new def entities_plural(self): return {entity.plural for entity in self.entities} def entities_by_singular(self): return {entity.key: entity for entity in self.entities}