forked from udacity/RL-Quadcopter-2
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replayBuffer.py
executable file
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/
replayBuffer.py
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import random
from collections import namedtuple, deque
class ReplayBuffer:
"""Fixed-size buffer to store experience tuples."""
def __init__(self, buffer_size, batch_size):
"""Initialize a ReplayBuffer object.
Params
======
buffer_size: maximum size of buffer
batch_size: size of each training batch
"""
self.memory = deque(maxlen=buffer_size) # internal memory (deque)
self.batch_size = batch_size
self.experience = namedtuple("Experience", field_names=["state", "action", "reward", "next_state", "done"])
def add(self, state, action, reward, next_state, done):
"""Add a new experience to memory."""
e = self.experience(state, action, reward, next_state, done)
self.memory.append(e)
def sample(self, batch_size=64):
"""Randomly sample a batch of experiences from memory."""
return random.sample(self.memory, k=self.batch_size)
def __len__(self):
"""Return the current size of internal memory."""
return len(self.memory)