python類的執行順序

class Foo():
    def __init__(self, x):
        print("this is class of Foo.")
        print("Foo類屬性初始化")
        self.f = "foo"
        print(x)

class Children(Foo):
    def __init__(self):
        y = 1
        print("this is class of Children.")
        print("Children類屬性初始化")
        super(Children, self).__init__(y)  # 進入`Foo類`中，向`Foo類`中傳入參數`y`,同時初始化`Foo類屬性`。
a = Children()
print(a)
print(a.f)

上面代碼，執行順序：
創建實例化對象：a = Children()
執行a：print(a)-->進入Childern類-->初始化Childern類參數，執行def __init__(self):下函數 -->進入Children父類Foo,傳入參數y並初始化父類Foo參數super(Children, self).__init__(y)，執行Foo中的參數初始化
輸出結果：

this is class of Children.
Children類屬性初始化
this is class of Foo.
Foo類屬性初始化
1
foo

類在神經網絡中的應用

class Net(nn.Module):
    def __init__(self):
        print("this is Net")
        self.a = 1
        super(Net, self).__init__()

    def forward(self, x):
        print("this is forward of Net", x)

class Children(Net):
    def __init__(self):
        print("this is children")
        super(Children, self).__init__()
a = Children()
a(1)

輸出：
this is children
this is Net
this is forward of Net 1

上面代碼執行順序：
創建實例化對象：a = Children()
執行a：進入Childern類 -->初始化Childern類參數，執行def __init__(self):內函數 -->進入Children父類Net,傳入參數y並初始化父類Net參數super(Children, self).__init__()，執行Foo中的參數初始化 -->傳入參數並執行父類Net的forward()函數a(1)