Circuit Breaker Pattern in Python: Closed, Open, and Half-Open States

class CircuitBreaker:
    def __init__(self, failure_threshold=3, timeout_seconds=5):
        self.failure_threshold = failure_threshold
        self.timeout_seconds = timeout_seconds
        self.state = "closed"
        self.failure_count = 0
        self.last_failure_time = None

    def record_success(self):
        if self.state == "half-open":
            self.state = "closed"
            print(f"Success in half-open -> state: {self.state}")
        self.failure_count = 0

    def record_failure(self):
        if self.state == "closed":
            self.failure_count += 1
            if self.failure_count >= self.failure_threshold:
                self.state = "open"
                self.last_failure_time = __import__("time").time()
                print(f"Threshold reached -> state: {self.state}")
        elif self.state == "half-open":
            self.state = "open"
            self.last_failure_time = __import__("time").time()
            print(f"Failure in half-open -> state: {self.state}")

    def check_state(self):
        if self.state == "open" and self.last_failure_time is not None:
            import time
            if time.time() - self.last_failure_time >= self.timeout_seconds:
                self.state = "half-open"
                print(f"Timeout elapsed -> state: {self.state}")
        return self.state


if __name__ == "__main__":
    cb = CircuitBreaker(failure_threshold=2, timeout_seconds=1)
    print(f"Initial state: {cb.state}")
    cb.record_failure()
    cb.record_failure()
    cb.check_state()
    cb.record_success()
    cb.check_state()