python-design-patterns/behavioral/visitor_pattern.py at main · 5iing/python-design-patterns · GitHub

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from abc import ABC, abstractmethod

class Visitor(ABC):
    @abstractmethod
    def visit(self, miner: "Miner") -> int: ...

class Miner(ABC):
    @abstractmethod
    def mine(self) -> None: ...

    @abstractmethod
    def accept_visit(self, visitor: "Visitor") -> int: ...

class IncomeVisitor(Visitor):
    def visit(self, miner: Miner) -> int:
        return miner.income

class TimesVisitor(Visitor):
    def visit(self, miner: Miner) -> int:
        return miner.times_ago

class BitcoinMiner(Miner):
    def __init__(self):
        self.income = 0
        self.times_ago = 0

    def mine(self) -> None:
        self.income += 100
        self.times_ago += 1
        print("im mining bitcoin")
        print(f"i got {self.income}$")

    def accept_visit(self, visitor: Visitor) -> int:
        return visitor.visit(self)

if __name__ == '__main__':
    miner = BitcoinMiner()
    income = IncomeVisitor()
    times = TimesVisitor()

    miner.mine()
    miner.mine()

    print("")

    now_income = miner.accept_visit(income)
    how_many_times = miner.accept_visit(times)
    print(f"{now_income}$, {how_many_times} times")