optimize.py issues with stretch and jessie

With stretch:

File "/usr/lib/python2.7/dist-packages/scipy/optimize/optimize.py", line 769
    with warnings.catch_warnings():
                     ^
SyntaxError: invalid syntax
_________________

With jessie:

File "/usr/lib/python2.7/dist-packages/scipy/optimize/optimize.py", line 17
from *future* import division, print_function, absolute_import
SyntaxError: future feature print_function is not defined

So, wherever one goes, a wall is found, or is that a wall for me alone?

francesco pietra