Stringio Portability Between Python2 And Python3 When Capturing Stdout

I have written a python package which I have managed to make fully compatible with both python 2.7 and python 3.4, with one exception that is stumping me so far. The package includ

Solution 1:

You replaced the Python 2 bytes-only sys.stdout with one that only takes Unicode. You'll have to adjust your strategy on the Python version here, and use a different object:

try:
    # Python 2from cStringIO import StringIO
except ImportError:
    # Python 3from io import StringIO

and remove the io. prefix in your context manager:

origout,  sys.stdout = sys.stdout, StringIO()

The cStringIO.StringIO object is the Python 2 equivalent of io.BytesIO; it requires that you write plain bytestrings, not aunicode objects.

You can also use io.BytesIO in Python 2, but then you want to test if sys.stdout is a io.TextIOBase subclass; if it is not, replace the object with a binary BytesIO, object, otherwise use a StringIO object:

import ioif isinstance(sys.stdout, io.TextIOBase):
    # Python 3
    origout, sys.stdout = sys.stdout, io.StringIO()
else:
    # Python 2or an unorthodox binary stdout setup
    origout, sys.stdout = sys.stdout, io.BytesIO()

Solution 2:

Have your tried? (Can be left in your code under Python 3.x)

from __future__ import unicode_literals

Else what I have in my code to make it compatible when using io.StringIO:

f = io.StringIO(datafile.read().decode('utf-8'), newline=None)

Looking at your code then:

yield (rtn, sys.stdout.read())

Could be changed to:

yield (rtn, sys.stdout.read().decode('utf-8'))