Add more useful help for special name in `help()`

Feature or enhancement

Proposal:

Now, use help("__name__") and some other special variables' names will still get the help from their class. I think that we can add the useful help on them. For example:

>>>help("__name__")
1. module.__name__ : if the module is run as the main module, the value is ‘_main_‘, or the name is the filename of the module. For example:if __name__ == "__main__": ...can control which code don’t run when the module is imported.

2. cls.__name__: the name of the class. It must be str.

For other special variables (such as __file__), we can alse print the similar detailed help. And I think that the sentences need to be friendly.

Also welcome to give the ideals on new ideas

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-137966

首先运行 help("name")，并将其当前输出与针对 name 和 file 提出的示例进行比较。当 help() 为所选特殊变量提供友好且有用的解释时，即表示完成；开始之前请先查看链接的 PR gh-137966。