sigmoid（）占用1个位置参数，但给出了2个

Question

为什么我收到此错误

  

sigmoid（）需要1个位置参数但是2个被赋予

使用函数yHat = NN.forward（X）??

class Neural_Networks(object):
    def __init__(self):
        self.inputLayerSize =2
        self.outputLayerSize =1
        self.hiddenLayerSize = 3
        #weights
        self.W1 = np.random.randn(self.inputLayerSize, self.hiddenLayerSize)
        self.W2 = np.random.randn(self.hiddenLayerSize, self.outputLayerSize)

    def forward(self,X):
        #propogates input through network
        self.z2 = np.dot(X, self.W1)
        self.a2 = self.sigmoid( self.z2 )
        self.Z3 = np.dot(self.a2,self.W2)
        yHat = self.sigmoid(self.z3)
        return yHat

    def sigmoid(z):
        return 1/(1+np.exp(-z))