[FIXED] Trying to make this code with subprocess.check_output python interpreter agnostic

Issue

I'm trying to run this code for multiple python interpreter version. I'm getting an error for python3+. I would like to know if it is possible to run this piece of code for both python interpreter versions.

output = subprocess.check_output(['ls', '-la'], **(dict() if sys.version_info[0] < 3 else dict(text=True)))
if sys.version_info < (3, 0):
    output = output.decode()

Works fine for python 2.x. But, for python3.x it output the fallowing error:

File "/usr/lib/python3.6/subprocess.py", line 356, in check_output **kwargs).stdout
  File "/usr/lib/python3.6/subprocess.py", line 423, in run
    with Popen(*popenargs, **kwargs) as process:
TypeError: __init__() got an unexpected keyword argument 'text'

Solution

"text" parameter is only available in version 3.7. Which means that your code will fail on an older python 3 version.

If you want to make it run on most versions, it's better to just forget about this, and use decode if you're using python 3. I like to use bytes is not str to check for this. But you can use a version check as well.

output = subprocess.check_output(['ls', '-la'])
if bytes is not str:
    output = output.decode()

you need to decode output because check_output returns a bytes object, which needs decoding in python 3 if you want it to be a str.

Decoding with python 2 would work but would return a unicode object. The above method guarantees to produce a str object whatever the version.

Answered By - Jean-François Fabre