re-open a Popen pipe in non-binary mode

[DeaD_EyE]

You can reuse the already opened Pipe.

Here two different approaches:

import os
import subprocess
import io

# Low Level approach
proc = subprocess.Popen(['cat'], stdin=subprocess.PIPE)
proc.stdin.fileno()
tw = os.fdopen(proc.stdin.fileno(), 'w', encoding='utf8')
tw.write('Hello World\n')
tw.flush()
proc.stdin.write(b'Hello World bytes\n')
proc.stdin.flush()
proc.stdin.close()

# tw is now also closed.

# different approach with io
proc = subprocess.Popen(['cat'], stdin=subprocess.PIPE)
tw2 = io.TextIOWrapper(proc.stdin, encoding='utf8')
tw2.write('Hello ...\n')
tw2.flush()
proc.stdin.write(b'Bin ...\n')
proc.stdin.flush()

tw2.close()
# will close also proc.stdin

The command cat reads from stdin.
It prints the data on the screen, when the pipe stdin was closed.