Discussion of sys module in Data Model

Documentation

In the section titled "I/O objects (also known as file objects)" in the Data Model chapter, it says:

The objects sys.stdin, sys.stdout and sys.stderr are initialized to file objects corresponding to the interpreter’s standard input, output and error streams; they are all open in text mode and therefore follow the interface defined by the io.TextIOBase abstract class.

However, neither the sys nor the io modules have been introduced (and probably should not be in this chapter). Is it appropriate to talk about module-specific features here? Or maybe this text should be modified to lean towards those objects just as examples of file objects?

Data Model の章の「I/O objects (also known as file objects)」セクションから始め、周辺の説明を読んで、sys と io への参照が適切に導入されているかを評価します。これらのモジュール固有の例を残すのか、それともこの記述を見直して file objects の例としてのみ提示するのかを判断できれば完了です。