无法在Python3中导入虾

我已经写了一段时间的reddit bot了，最近又将它移到了另一个系统上。在那里，我安装了与以前的系统相同的软件包。

该机器人是基于Python3的，因此我安装了praw：

$ sudo pip3 install praw
[...]

一切都按预期进行，但是现在当我import praw：

$ python3
Python 3.4.2 (default, Oct  8 2014, 10:45:20) 
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import praw
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.4/dist-packages/praw/__init__.py", line 14, in <module>
    from .reddit import Reddit  # NOQA
  File "/usr/local/lib/python3.4/dist-packages/praw/reddit.py", line 11, in <module>
    from prawcore import (Authorizer, DeviceIDAuthorizer, ReadOnlyAuthorizer,
ImportError: No module named 'prawcore'

即使在手动将路径添加到模块后，也无法导入praw。

>>> import sys
>>> sys.path.append('/usr/local/lib/python3.4/dist-packages/')
>>> import praw
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.4/dist-packages/praw/__init__.py", line 14, in <module>
    from .reddit import Reddit  # NOQA
  File "/usr/local/lib/python3.4/dist-packages/praw/reddit.py", line 11, in <module>
    from prawcore import (Authorizer, DeviceIDAuthorizer, ReadOnlyAuthorizer,
ImportError: No module named 'prawcore'

使用python（2），似乎工作正常。

如何使我的系统成功导入praw？