1209 ValueError: too many values to unpack (expected 4)

19：43
ValueError: too many values to unpack (expected 4)

19：49

SyntaxError: invalid character in identifier

解释器提示如：SyntaxError: invalid character in identifier， 但又一直找不到问题点的话，请确保代码行内没有夹杂中文的空格，tab等，非文字字符．

22：04

RuntimeWarning: invalid value encountered in double_scalars
cost += self.cost.fn(a, y)/len(data)

RuntimeWarning: divide by zero encountered in log
return np.sum(np.nan_to_num(-y*np.log(a)-(1-y)*np.log(1-a)))

22：08

白色运行结果：

注释掉的运行结果：