Python:如何从成员函数中调用构造函数 [英] Python: How to call the constructor from within member function

问题描述

此问题/解答(成员函数中的Python调用构造函数)说，可以从在成员函数中.

This Question / Answer (Python call constructor in a member function) says it is possible to to call the constructor from within a member function.

我该怎么做?

这是一种好风格吗?

我用以下代码尝试过:

class SomeClass(object):
    def __init__(self, field):
        self.field = field

    def build_new(self):
        self = SomeClass(True)

def main():
    inst = SomeClass(False)
    inst.build_new()
    print(inst.field)

if __name__ == '__main__':
    main()

作为输出，我得到:错误

As output I get: False

自从我调用了 build_new()方法以来， inst.field 是否应该为 True ?

Since I called the build_new() method inst.field should be True or not?

推荐答案

我相信您正在寻找的只是再次调用 init 函数.

I believe what you are looking for is just calling the init function again.

class SomeClass(object):
    def __init__(self, field):
        self.field = field

    def build_new(self):
        self.__init__(True)

这将导致字段变量设置为True而不是False.基本上，您是在重新初始化实例，而不是创建一个全新的实例.

This will cause the field variable to be set to True over False. Basically, you are re-initializing the instance rather than creating a brand new one.

您当前的代码创建一个新实例，并且在超出范围(即函数返回)时丢失对它的引用，因为您只是将self的名称重新绑定到一个不同的值，而实际上并没有改变self的内部内容

Your current code creates a new instance and just loses the reference to it when it goes out of scope (i.e. the function returning) because you are just rebinding the name of self to a different value not actually changing the inner contents of self.

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