How to copy data to clipboard

[snippsat]

Can also mention that your subprocess code is wrong.
When commands in a list call(recommended),then can not use shell=True.
Also use capture_output=True to catch stdout from xsel.

from subprocess import run

err = run(['xsel', '--clipboard'], capture_output=True, encoding='utf-8')
print(err.stdout)

Output:
hello this text is from clipboard

An other library is jaraco.clipboard which can do html/image format to.
As @buran mention so may there be other way to do this,that may be just easy as copy content from clipboard.