No output from Python subprocess

Question

I'm using Python 3.5.1 and Windows 10. I can't get subprocess to put output to the screen. So let's start with something simple:

import subprocess
process = subprocess.run('echo hi', shell=True, stdout=subprocess.PIPE)

When I run my python module, I want to it to print 'hi' in the Python Shell. The script runs and does not return an error, but it prints nothing to the screen.

I have also tried many different flavors of subprocess (i.e. Popen), but still no luck. I have a feeling this has something to do with the way my Windows/Python environment is setup, but I don't really know where to start. Thoughts?

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Update

So I now understand that my original code sample should not have put anything on the screen; however, when I run

import subprocess
p = subprocess.run('echo hi', shell=True)

I get no output. When I run:

import subprocess
p = subprocess.run('echo hi', shell=True, stdout=subprocess.PIPE)
print(p.stdout)

I do get output. Why did the first example not work?

Answer 1

It's not printing to the screen because you're redirecting the output to a PIPE. Remove the pipe argument and the output will go to the normal stdout

You can use subprocess.call also.

subprocess.call('echo hi', shell=True)

If you want to pipe the output, you should use Popen instead

process = subprocess.Popen('echo hi', shell=True, stdout=subprocess.PIPE)
process.wait()
print process.stdout.read()

If you want to decode the result as UTF-8 format, just add .decode('UTF-8')

process.stdout.read().decode('utf-8')