“**kwargs”和“**initkwargs”功能的不同

In Django's source code, there are **kwargs and **initkwargs. django/base.py at master · django/django

在Django的源代码中，有**kwargs和**initkwargs。django /基地。py at master·django/django

class View:

    def __init__(self, **kwargs):
        """
        Constructor. Called in the URLconf; can contain helpful extra
        keyword arguments, and other things.
        """
        # Go through keyword arguments, and either save their values to our
        # instance, or raise an error.
        for key, value in kwargs.items():
            setattr(self, key, value)

and

和

    @classonlymethod
    def as_view(cls, **initkwargs):
        """Main entry point for a request-response process."""
        for key in initkwargs:
            if key in cls.http_method_names:
                raise TypeError("You tried to pass in the %s method name as a "
                                "keyword argument to %s(). Don't do that."
                                % (key, cls.__name__))

What's difference of them in usage?

它们在使用上有什么不同?

2 个解决方案

#1

While kwargs is the conventional name, the main reason it is called initkwargs is to avoid name conflicts:

虽然kwargs是传统名称，但它被称为initkwargs的主要原因是为了避免名称冲突:

@classonlymethod
def as_view(cls, **initkwargs):
    """Main entry point for a request-response process."""
    ...

    def view(request, *args, **kwargs):  # defines kwargs
        self = cls(**initkwargs)         # uses initkwargs
        ...
        return self.dispatch(request, *args, **kwargs)
    ...
    return view

Note that the inner view function takes a **kwargs parameter. If the classmethod used the same name, the inner **kwargs would shadow the outer **kwargs, and the function wouldn't be able to access the outer kwargs when instantiating cls.

注意，内部视图函数使用**kwargs参数。如果classmethod使用相同的名称，那么内部的**kwargs将对外部的**kwargs进行阴影处理，在实例化cls时，函数将无法访问外部的kwargs。

Using the name initkwargs avoids this issue.

使用initkwargs名称可以避免这个问题。

#2

As a comment says, there is no difference between the two regarding the mechnics behind it. The important part is the **. That being said, I'd like to add the distinction from the two seems to comes from the fact that **initkwargs is use for class instanciation. Indeed, it is always use in conjunction with cls which normally stands for the first argument to class methods (PEP 8).

正如一篇评论所说，这两者对于背后的机制并没有什么区别。重要的部分是**。话虽如此，我还是想补充一下两者之间的区别似乎来自于**initkwargs用于类实例化这一事实。实际上，它总是与cls一起使用，cls通常代表类方法的第一个参数(PEP 8)。

So even though there is not much difference between the two and that it may only be a good pratice, I would not say that this is irrelevant.

因此，尽管这两者之间并没有太大的区别，这可能只是一个很好的实践，但我不会说这是无关紧要的。

#1