在Python2.7和3.2中导入内核密度

我正在尝试使用以下页面上的示例学习scikit：

我的机器上安装了Python2.7和3.2（Ubuntu 12.04）。当我在2.7中尝试以下行时

from sklearn.neighbors import KernelDensity

我得到以下错误：

Python 2.7.3 (default, Feb 27 2014, 20:00:17) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from sklearn.neighbors import KernelDensity
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: cannot import name KernelDensity

Python 3.2.3 (default, Feb 27 2014, 21:33:50) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from sklearn.neighbors import KernelDensity
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/dist-packages/sklearn/neighbors/__init__.py", line 6, in <module>
    from .ball_tree import BallTree
  File "numpy.pxd", line 155, in init sklearn.neighbors.ball_tree (sklearn/neighbors/ball_tree.c:34290)
ValueError: numpy.dtype has the wrong size, try recompiling

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/dist-packages/sklearn/__init__.py", line 38, in <module>
    from .base import clone
  File "/usr/local/lib/python3.2/dist-packages/sklearn/base.py", line 10, in <module>
    from scipy import sparse
  File "/usr/lib/python3/dist-packages/scipy/__init__.py", line 124, in <module>
    pkgload(verbose=SCIPY_IMPORT_VERBOSE,postpone=True)
  File "/usr/local/lib/python3.2/dist-packages/numpy/_import_tools.py", line 177, in __call__
    for package_name in self._get_sorted_names():
  File "/usr/local/lib/python3.2/dist-packages/numpy/_import_tools.py", line 114, in _get_sorted_names
    for name in depend_dict.keys():
RuntimeError: dictionary changed size during iteration

我还运行了以下程序：

sudo -E pip install -U scikit-learn

它返回：

Requirement already up-to-date: scikit-learn in /usr/local/lib/python3.2/dist-packages
Cleaning up...

我最近一直在学习python，随着我在理解python语言方面的进步，我已经开始学习“sklearn”，但由于这个错误，我陷入了困境。我怎么修理它

在尝试不同的选项时，我还升级了numpy（到1.8.1版），在按照建议使用pip卸载和重新安装scikit learn后，我遇到以下错误：

Python 2.7.3 (default, Feb 27 2014, 20:00:17) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from sklearn.neighbors import KernelDensity
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: cannot import name KernelDensity

Python 3.2.3 (default, Feb 27 2014, 21:33:50) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from sklearn.neighbors import KernelDensity
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/dist-packages/sklearn/neighbors/__init__.py", line 6, in <module>
    from .ball_tree import BallTree
  File "numpy.pxd", line 155, in init sklearn.neighbors.ball_tree (sklearn/neighbors/ball_tree.c:34290)
ValueError: numpy.dtype has the wrong size, try recompiling

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/dist-packages/sklearn/__init__.py", line 38, in <module>
    from .base import clone
  File "/usr/local/lib/python3.2/dist-packages/sklearn/base.py", line 10, in <module>
    from scipy import sparse
  File "/usr/lib/python3/dist-packages/scipy/__init__.py", line 124, in <module>
    pkgload(verbose=SCIPY_IMPORT_VERBOSE,postpone=True)
  File "/usr/local/lib/python3.2/dist-packages/numpy/_import_tools.py", line 177, in __call__
    for package_name in self._get_sorted_names():
  File "/usr/local/lib/python3.2/dist-packages/numpy/_import_tools.py", line 114, in _get_sorted_names
    for name in depend_dict.keys():
RuntimeError: dictionary changed size during iteration

回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/usr/local/lib/python3.2/dist-packages/sklearn/_init__.py”，第38行，在
从.base导入克隆
文件“/usr/local/lib/python3.2/dist-packages/sklearn/base.py”，第10行，在
从scipy导入稀疏
文件“/usr/lib/python3/dist-packages/scipy/_-init__.py”，第124行，在
pkgload（verbose=SCIPY\u IMPORT\u verbose，delayer=True）
文件“/usr/local/lib/python3.2/dist packages/numpy/\u import\u tools.py”，第177行，在调用中__
对于self中的包名称。\u获取\u排序\u名称（）：
文件“/usr/local/lib/python3.2/dist-packages/numpy/\u-import\u-tools.py”，第114行，在“获取排序”名称中
对于depend_dict.keys（）中的名称：
RuntimeError:字典在迭代期间更改了大小

尝试卸载已安装的scikit learn，然后使用pip重新安装。我刚刚这么做了，现在我遇到了一个新错误-刚刚用它更新了我的帖子。我已经升级了numpy的基础上一些谷歌。