How to display text in terminal when redirecting stdout and stderr streams in Ubuntu 18.04?

Question

Python

There is a python file.
When working, it issues a greeting through print () and requests data.
If the data is entered correctly, then it outputs the result through sys.stdout,
if not, then through sys.stderr
In the terminal, everything works fine.
I need to redirect streams to out.txt and err.txt
I do everything with the command: python3 ./interacter.py >out.txt 2>err.txt
Everything works, I can enter data through the terminal, but the greeting and result are not displayed, although everything is written to files.
How to make the information displayed in the terminal when redirecting streams?

Answer 1

tee