项目场景：

进行ReLU类的实例运算时，出现了问题

---

问题描述

import numpy as np

class ReLU():
    def __init__(self):
        self.mask = None
    
    def forward(self, x):
        self.mask = (x <= 0)
        out = x.copy()
        out[self.mask] = 0
        
        return out
    
    def backward(self, dout):
        dout[self.mask] = 0
        dx = dout
        
        return dx
    
a = np.array([[1.0, -0.5], [-2.0, 3.0]])
relu = ReLU()
out = ReLU.forward(a)
print(out)

  运行程序时会出现报错：

runfile('C:/Users/Administrator/.spyder-py3/temp.py', wdir='C:/Users/Administrator/.spyder-py3')
Traceback (most recent call last):

  File "C:\Users\Administrator\.spyder-py3\temp.py", line 22, in <module>
    out = ReLU.forward(a)

TypeError: forward() missing 1 required positional argument: 'x'

 

---

原因分析：

看22行，前面已经将类赋给了relu，在下一行调用内部函数的时候，要用relu，不应该用原来类的名称ReLU.

---

解决方案：

import numpy as np

class ReLU():
    def __init__(self):
        self.mask = None
    
    def forward(self, x):
        self.mask = (x <= 0)
        out = x.copy()
        out[self.mask] = 0
        
        return out
    
    def backward(self, dout):
        dout[self.mask] = 0
        dx = dout
        
        return dx
    
a = np.array([[1.0, -0.5], [-2.0, 3.0]])
relu = ReLU()
out = relu.forward(a)
print(out)

    

结果：

[[1. 0.]
 [0. 3.]]

在运用类的时候，要先实例化类，然后用实例化之后的名称进一步调用类内部的函数。