cd Boost-Python-Examples/Examples/class_property
make
python3

Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import class_property
>>> num = class_property.Num()
>>> num.rovalue
10.0
>>> num.value
10.0
>>> num.value = 3
>>> num.value
3.0
>>> num.rovalue = 3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: can't set attribute