[New-bugs-announce] [issue46988] if a python program is execute by subprocess, the python program can't output unicode characters and raise UnicodeEncodeError

[markhuang3310]

New submission from markhuang3310 <markhuang3310 at gmail.com>:

Env:
Windows 10
Python3.8.10 amd64

Desciption:

I try to get output from a python program with a subprocess.
The python program print a unicode character.

```
import subprocess
import sys
cmd = rf'''{sys.executable} -c "print('\u042f')"'''

print('case 1')
stdout, stderr =  subprocess.Popen(cmd, stderr=subprocess.PIPE, stdout=None).communicate()
print('case 2')
stdout, stderr =  subprocess.Popen(cmd, stderr=subprocess.PIPE, stdout=subprocess.PIPE).communicate()
print(stderr)
```

The issue is that:
In case 1, I can see the "Я" (\u042f) form console.
In case 2, I try to get the output from subprocess.Popen(command).communicate()[0], the python process fail with   UnicodeEncodeError.

Expected result:
In case2, I should get stdout == b'\u042f'

----------
components: Windows
files: test.py
messages: 414919
nosy: markhuang3310, paul.moore, steve.dower, tim.golden, zach.ware
priority: normal
severity: normal
status: open
title: if a python program is execute by subprocess, the python program  can't output unicode characters and raise UnicodeEncodeError
type: behavior
versions: Python 3.8
Added file: https://bugs.python.org/file50667/test.py

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue46988>
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