How to connect to database via subprocess.Popen()?

Question

Python

windows 7, visual studio 2017, PostgreSQL 11, Python 3.6.
I'm trying to connect to the database:

args = [ "C://Program files/Postgresql/11/bin/psql.exe", "-d Test", "-U postgres"]
process = subprocess.Popen(args, stdout = subprocess.PIPE)
data = process.communicate()
print(data)

The command runs, it asks for a password, when I enter the password, it outputs:
psql: IMPORTANT: the user "postgres" is not authenticated (by password)
(b'', None)
If you run the appropriate command from the console and enter the same password, everything enters normally.
I tried to set trust in the config so that it would not ask for a password at all, I get the following error:
psql: IMPORTANT: the role "postgres" does not exist (b'', None)