导入安装了不同版本的python包

Question

我有问题。我正在尝试安装用python编写的脚本。它需要3.4+版本，默认情况下我的ubuntu 15.10上安装了python2.7 python3.4 python3.5。在安装过程中，它会抛出一个错误，我发现它与python中缺少的包有关。

错误是

File "/usr/lib/python3.4/distutils/dist.py", line 1209, in set_requires distutils.versionpredicate.VersionPredicate(v)
File "/usr/lib/python3.4/distutils/versionpredicate.py", line 114, in __init__ raise ValueError("expected parenthesized list: %r" % paren) 
ValueError: expected parenthesized list: '-branch'

我查看了源代码，找到了所需包的列表，并制作了一个小脚本，让我找不到它们

import pip
installed_packages = pip.get_installed_distributions()
flat_installed_packages = [package.project_name for package in installed_packages]
packages = [
    "aiohttp",
    "httplib2",
    "socksipy-branch",
    "requests",
    "dns",
    "url"
]
for needle in packages:
    if needle in flat_installed_packages:
        print('Found ', needle)
    else:
        print('Not found ', needle)`

输出

Found  aiohttp
Found  httplib2
Not found  socksipy-branch
Found  requests
Not found  dns
Found  url

我尝试用synaptic manager安装这些，手动使用apt-get，使用pip，pip3，pip3.4，但没有运气。正如我在包安装过程中从随机消息中看到的那样，无论我做什么，它都会将它们安装到python 2.7中。如何将它们变成3.4版本？请帮帮我。