Python - AttributeError: 'tuple' 对象没有属性 'fire'

我正在学习制作一个基本的神经网络，我正在尝试制作一个可以在 python 中将数字相加的网络，但我不断收到此错误：

Traceback (most recent call last):
  File "C:/Users/tomas/Desktop/projects/neuralnetwork/main.py", line 37, in <module>
    class Main:
  File "C:/Users/tomas/Desktop/projects/neuralnetwork/main.py", line 76, in Main
    out.fire()
  File "C:/Users/tomas/Desktop/projects/neuralnetwork/main.py", line 23, in fire
    i.fire()
AttributeError: 'tuple' object has no attribute 'fire'

我是 python 新手，所以如果我犯了一些明显的错误，请原谅我。

代码：

class Synapse:
    origin = None
    weight, learningRate = 0.5, 0.25

    def __init__(self, origin):
        self.origin = origin

    def adjust_weight(self, result, expected):
        self.weight *= self.learningRate * (expected - result)


class Neuron:
    threshold, output = None, None
    inputs = []

    def __init__(self, threshold, output):
        self.threshold = threshold
        self.output = output

    def fire(self):
        weighed_input = 0
        for i in self.inputs:
            i.fire()
            weighed_input += i.weight * i.origin.output
        if weighed_input >= self.threshold:
            self.output = weighed_input
        else:
            self.output = 0

    def connect_synapse(self, *synapse):
        self.inputs.append(synapse)

    def clear_synapses(self):
        self.inputs = []

class Main:
    training_data = [[[1, 2], [3]],
                     [[2, 0], [2]],
                     [[1, 1], [2]],
                     [[3, 0], [3]],
                     [[3, 1], [4]]]

    src1 = Neuron(0, None)
    src2 = Neuron(0, None)

    hid1 = Neuron(1, None)
    hid2 = Neuron(1, None)

    out = Neuron(0, None)

    syn1 = Synapse(src1)
    syn2 = Synapse(src2)
    syn3 = Synapse(hid1)
    syn4 = Synapse(hid2)

    while True:
        error_count = 0

        hid1.clear_synapses()
        hid2.clear_synapses()
        hid1.connect_synapse(syn1, syn2)
        hid2.connect_synapse(syn1, syn2)

        out.clear_synapses()
        out.connect_synapse(syn3, syn4)

        for i in range(0, 5):
            input1 = training_data[i][0][0]
            input2 = training_data[i][0][1]
            expected = training_data[i][1][0]

            src1.output = input1
            src2.output = input2

            out.fire()
            result = out.output
            if result != expected:
                error_count += 1
                syn1.adjust_weight(result, expected)
                syn2.adjust_weight(result, expected)

             print("Expected ", expected, "\nGot ", result, "\nError count: ", error_count, "\n\n")

        if error_count == 0:
            break

提前致谢。