Python n'est pas correctement installer

Bonjour,
je n'arrive pas a lancer xcat , voici mon erreur :
ollecting xcat
Using cached xcat-0.7.1.zip
Collecting aiohttp (from xcat)
Using cached aiohttp-1.0.5.tar.gz
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/tmp/pip-build-VzKF2X/aiohttp/setup.py", line 60, in <module>
raise RuntimeError("aiohttp requires Python 3.4.2+")
RuntimeError: aiohttp requires Python 3.4.2+

----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-VzKF2X/aiohttp/