class TaxAvoidance:
    """
    #### A class to represent tax avoidance, which involves using legal methods to minimize tax liability through tax planning strategies.

    Attributes
    ----------
    company_name : str
        the name of the company
    business_activities : str
        the type of business activities the company is involved in
    industry : str
        the industry in which the company operates
    tax_laws_compliance : bool
        a flag indicating whether the company is in compliance with all applicable tax laws and regulations
    tax_strategies : list
        a list of tax planning strategies implemented by the company

    Methods
    -------
    add_tax_strategy(strategy: str):
        Adds a tax planning strategy to the list of tax strategies implemented by the company.

    remove_tax_strategy(strategy: str):
        Removes a tax planning strategy from the list of tax strategies implemented by the company.

    get_tax_liability() -> float:
        Calculates the company's tax liability based on its financial activities and the tax strategies implemented.
    """

    def __init__(self, independent,company_name, business_activities, industry):
        """
        Constructs all the necessary attributes for the TaxAvoidance object.

        Parameters
        ----------
        company_name : str
            the name of the company
        business_activities : str
            the type of business activities the company is involved in
        industry : str
            the industry in which the company operates
        """
        self.company_name = company_name
        self.business_activities = business_activities
        self.industry = industry
        self.tax_laws_compliance = True
        self.tax_strategies = []
        self._independent = independent
        self._independent.attach(self)
        self._dependents = []
    def attach(self, dependent):
        self._dependents.append(dependent)
    def detach(self, dependent):
        self._dependents.remove(dependent)
    def notify(self):
        for dependent in self._dependents:
            dependent.update()
    def update(self):
        # 观察者收到通知后需要执行的操作
        print("Received notification from subject.")
    def add_tax_strategy(self, strategy: str):
        """
        Adds a tax planning strategy to the list of tax strategies implemented by the company.

        Parameters
        ----------
        strategy : str
            the tax planning strategy to be added
        """
        self.tax_strategies.append(strategy)

    def remove_tax_strategy(self, strategy):
        """
        Removes a tax planning strategy from the list of tax strategies implemented by the company.

        Parameters
        ----------
        strategy : str
            the tax planning strategy to be removed
        """
        self.tax_strategies.remove(strategy)

    def get_tax_liability(self):
        """
        Calculates the company's tax liability based on its financial activities and the tax strategies implemented.

        Returns
        -------
        float
            the company's tax liability
        """
        # implementation details to calculate the company's tax liability

