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

首先執行 help("name")，並將其目前的輸出與針對 name 和 file 提出的範例進行比較。當 help() 為所選的特殊變數提供友善且有用的說明時，即表示完成；開始之前請先查看連結的 PR gh-137966。