Leaky Bucket Rate Limiter in Python: Smooth Burst Traffic

import time
import random


class LeakyBucket:
    def __init__(self, capacity, drain_rate):
        self.capacity = capacity
        self.drain_rate = drain_rate
        self.water = 0.0
        self.last_time = time.time()

    def allow(self, packet_size=1.0):
        now = time.time()
        elapsed = now - self.last_time
        self.last_time = now
        self.water = max(0.0, self.water - elapsed * self.drain_rate)
        if self.water + packet_size <= self.capacity:
            self.water += packet_size
            return True
        return False


def mock_burst_traffic(bucket, events):
    accepted = 0
    dropped = 0
    for _ in range(events):
        packet = random.uniform(0.5, 2.0)
        if bucket.allow(packet):
            accepted += 1
        else:
            dropped += 1
        time.sleep(0.01)
    return accepted, dropped


if __name__ == "__main__":
    random.seed(42)
    bucket = LeakyBucket(capacity=5.0, drain_rate=2.0)
    accepted, dropped = mock_burst_traffic(bucket, 100)
    print(f"Accepted: {accepted}, Dropped: {dropped}")
    print(f"Dropped ratio: {dropped / 100:.2%}")