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@alirezamika
Last active December 27, 2020 10:04
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from collections import defaultdict
class Q:
def __init__(self, alpha=0.5, discount=0.5):
self.alpha = alpha
self.discount = discount
self.values = defaultdict(lambda: defaultdict(lambda: 0.0))
def update(self, state, action, next_state, reward):
value = self.values[state][action]
v = list(self.values[next_state].values())
next_q = max(v) if v else 0
value = value + self.alpha * (reward + self.discount * next_q - value)
self.values[state][action] = value
def get_best_action(self, state):
keys = list(self.values[state].keys())
if not keys:
return None
return max(keys, key=lambda x: self.values[state][x])
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