python - Python 链式属性访问中的无传播

Question

这个问题在这里已经有了答案:





Is there a Python equivalent to the C# ?. and ?? operators?

(1 个回答)



Is there a Python equivalent of the C# null-coalescing operator?

(11 个回答)


去年关闭。




有没有空传播运算符 (“null-aware member access”操作符)在 Python 中，所以我可以写一些类似的东西

var = object?.children?.grandchildren?.property

就像在 C#、VB.NET 和 TypeScript 中一样，而不是

var = None if not myobject\
              or not myobject.children\
              or not myobject.children.grandchildren\
    else myobject.children.grandchildren.property

Answer 1

没有。有一个PEP proposing the addition of such operators但它还没有(还)被接受。

特别是，PEP 505 中提出的算子之一是

The "None-aware attribute access" operator ?. ("maybe dot") evaluates the complete expression if the left hand side evaluates to a value that is not None