How do I pipe Unicode into a native application in PowerShell

Question

I have a native program written in Python that expects its input on stdin. As a simple example,

#!python3
import sys
with open('foo.txt', encoding='utf8') as f:
    f.write(sys.stdin.read())

I want to be able to pass a (PowerShell) string to this program as standard input. Python expects its standard input in the encoding specified in $env:PYTHONIOENCODING, which I will typically set to UTF8 (so that I don't get any encoding errors).

But no matter what I do, characters get corrupted. I've searched the net and found suggestions to change [Console]::InputEncoding/[Console]::OutputEncoding, or to use chcp, but nothing seems to work.

Here's my basic test:

PS >[Console]::OutputEncoding.EncodingName
Unicode (UTF-8)
PS >[Console]::InputEncoding.EncodingName
Unicode (UTF-8)
PS >$env:PYTHONIOENCODING
utf-8
PS >python -c "print('\N{Euro sign}')" | python -c "import sys; print(sys.stdin.read())"
´╗┐?

PS >chcp 1252
Active code page: 1252
PS >python -c "print('\N{Euro sign}')" | python -c "import sys; print(sys.stdin.read())"
?

PS >chcp 65001
Active code page: 65001
PS >python -c "print('\N{Euro sign}')" | python -c "import sys; print(sys.stdin.read())"
 ?

How can I fix this problem?

I can't even explain what's going on here. Basically, I want the test (python -c "print('\N{Euro sign}')" | python -c "import sys; print(sys.stdin.read())") to print out a Euro sign. And to understand why, I have to do whatever is needed to get that to work :-) (Because then I can translate that knowledge to my real scenario, which is to be able to write working pipelines of Python programs that don't break when they encounter Unicode characters).

Answer 1

Thanks to mike z, the following works:

$OutputEncoding = [Console]::OutputEncoding = (new-object System.Text.UTF8Encoding $false)
$env:PYTHONIOENCODING = "utf-8"
python -c "print('\N{Euro sign}')" | python -c "import sys; print(sys.stdin.read())"

The new-object is needed to get a UTF-8 encoding without a BOM. The $OutputEncoding variable and [Console]::OutputEncoding both appear to need to be set.

I still don't fully understand the difference between the two encoding values, and why you would ever have them set differently (which appears to be the default).