Is it possible to change the python version used by syntastic for syntax checking?
As the Issue https://github.com/scrooloose/syntastic/issues/385 indicates I could use virtual-env. But is it also possible just with syntastic or vim commands?
From the Syntastic repository README:
Q. The python checker complains about syntactically valid Python 3 constructs...
A. Configure the python checker to call a Python 3 interpreter rather than Python 2, e.g:
let g:syntastic_python_python_exec = '/path/to/python3'
Add that line to your .vimrc - that should fix your problem.