On my Ubutntu machine i have both python 2.7 and 3.5. I've installed pysvn according tointruction here
sudo apt-get install python-svn
sudo apt-get install svn-workbench
Python 2.7 sees it, but not 3.5:
Python 3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysvn
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named 'pysvn'
>>>