[py3] Explained @python_2_unicode_compatible usage

    my_string = "This is an unicode literal"

    my_bytestring = b"This is a bytestring"

If you need a byte string under Python 2 and a unicode string under Python 3,

use the :func:`str` builtin::

In classes, define ``__str__`` methods returning unicode strings and apply the

:func:`~django.utils.encoding.python_2_unicode_compatible` decorator. It will

define appropriate ``__unicode__`` and ``__str__`` in Python 2::

    from __future__ import unicode_literals

    from django.utils.encoding import python_2_unicode_compatible

    @python_2_unicode_compatible

    class MyClass(object):

        def __str__(self):

            return "Instance of my class"

If you need a byte string literal under Python 2 and a unicode string literal

under Python 3, use the :func:`str` builtin::

    str('my string')