行首的 @ 符号用于类、函数和方法装饰器.

An @ symbol at the beginning of a line is used for class, function and method decorators.

在此处阅读更多信息:

PEP 318:装饰器

Python 装饰器

您将遇到的最常见的 Python 装饰器是:

The most common Python decorators you'll run into are:

@property

@classmethod

@staticmethod

如果你在一行的中间看到一个 @，那就是另一回事了，矩阵乘法.请参阅此答案，显示将 @ 用作二元运算符.

If you see an @ in the middle of a line, that's a different thing, matrix multiplication. See this answer showing the use of @ as a binary operator.