BP_GitChat

代码说明：

说明：  BP(back propagation)神经网络是1986年由Rumelhart和McClelland为首的科学家提出的概念，是一种按照误差逆向传播算法训练的多层前馈神经网络，是目前应用最广泛的神经网络，py实现(BP (back propagation) neural network is a concept put forward by Rumelhart and McClelland in 1986. It is a multi-layer feedforward neural network trained by error back propagation algorithm. It is the most widely used neural network at present.)