安装scikit时出错-学习python3

Question

因此，我能够为python2安装sklearn，但由于某些原因，我对python3也有问题。我得到了这个错误：

Traceback (most recent call last):
  File "/home/ajshack_pg/sklearn/__check_build/__init__.py", line 44, in <module>
    from ._check_build import check_build  # noqa
ImportError: /home/ajshack_pg/sklearn/__check_build/_check_build.so: undefined symbol: PyUnicodeUCS4_DecodeUTF8

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ajshack_pg/sklearn/__init__.py", line 133, in <module>
    from . import __check_build
  File "/home/ajshack_pg/sklearn/__check_build/__init__.py", line 46, in <module>
    raise_build_error(e)
  File "/home/ajshack_pg/sklearn/__check_build/__init__.py", line 41, in raise_build_error
    %s""" % (e, local_dir, ''.join(dir_content).strip(), msg))
ImportError: /home/ajshack_pg/sklearn/__check_build/_check_build.so: undefined symbol: PyUnicodeUCS4_DecodeUTF8
___________________________________________________________________________
Contents of /home/ajshack_pg/sklearn/__check_build:
setup.py                  setup.pyc                 __init__.pyc
_check_build.so           __init__.py
___________________________________________________________________________
It seems that scikit-learn has not been built correctly.

If you have installed scikit-learn from source, please do not forget
to build the package before using it: run `python setup.py install` or
`make` in the source directory.

If you have used an installer, please check that it is suited for your
Python version, your operating system and your platform.

我试着进入源目录，输入他们说的话，但没有结果。这里有洞察力吗？

谢谢!

Answer 1

如果您从Python2.x的源代码中安装了sklearn，如果您没有完全删除所有sklearn文件，它的一些二进制文件可能会持续存在。Python2.x和3.x非常不兼容，所以这可能是它无法构建的原因之一。

需要采取的几个步骤：

1. 考虑在您的sklearn项目中使用virtualenv，特别是当您有许多不同的包或Python版本浮动时。这对于使用不同的Python包和库保持不同的开发环境是很好的。如果您还没有本指南，请跟随它。在创建virtualenv时，请确保在创建virtualenv时使用以下命令使用Python 3.x安装它： virtualenv -p python3 envname
2. 如果从源代码构建：为您的Python3版本重新下载sklearn源代码，并将其放入您的虚拟环境中。严格遵循所有构建说明。这应该会给你一个干净的安装滑雪。
3. 如果使用pip:安装，则激活您的虚拟主机，然后是:安装numpy和scipy之后的pip install -U scikit-learn。