Writing bytes to standard output in a way compatible with both, python2 and python3
binary, python, python-3.x, stdout
Solution
No need to test, just use `getattr()`:
# retrieve stdout as a binary file object
output = getattr(sys.stdout, 'buffer', sys.stdout)
This retrieves the `.buffer` attribute on `sys.stdout`, but if it doesn't exist (Python 2) it'll return the `sys.stdout` object itself instead.
Python 2:
>>> import sys
>>> getattr(sys.stdout, 'buffer', sys.stdout)
<open file '<stdout>', mode 'w' at 0x100254150>
Python 3:
>>> import sys
>>> getattr(sys.stdout, 'buffer', sys.stdout)
<_io.BufferedWriter name='<stdout>'>
Take into account that in Python 2, `stdout` is still opened in text mode, newlines are still translated to `os.linesep` when writing. The Python 3 `BufferedWriter` object won't do this for you.
Problem
I want a function returning a file object with which I can write binary data to standard output. In python2 `sys.stdout` is such an object. In python3 it is `sys.stdout.buffer`. What is the most elegant/preferred way to retrieve such an object so that it works for both, the python2 and the python3 interpreter? Is the best way to check for existance of `sys.stdout.buffer` (probably using the `inspect` module) and if it exists, return it and if it doesnt, assume we are on python2 and return `sys.stdout` instead?