plf*_*ick 2 heroku python-2.7 scikit-learn python-venv
我正在尝试在虚拟环境中使用 scikit-learn，但无法运行。
例如，我转到一个项目文件夹并安装 NumPy、SciPy 和 scikit-learn
virtualenv venv
source venv/bin/activate
pip install numpy
pip install scipy
pip install scikit-learn
然后我打开 python 并尝试导入它们中的每一个。
import numpy
import scipy
import sklearn
NumPy 和 SciPy 导入正常，但是当我尝试导入时，出现错误提示Library not loaded: @rpath/./libgfortran.3.dylib.
我在安装中缺少什么吗？
完整的错误信息：
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/sklearn/__init__.py", line 57, in <module>
from .base import clone
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/sklearn/base.py", line 11, in <module>
from .utils.fixes import signature
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/sklearn/utils/__init__.py", line 11, in <module>
from .validation import (as_float_array,
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/sklearn/utils/validation.py", line 16, in <module>
from ..utils.fixes import signature
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/sklearn/utils/fixes.py", line 324, in <module>
from scipy.sparse.linalg import lsqr as sparse_lsqr
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/scipy/sparse/linalg/__init__.py", line 109, in <module>
from .isolve import *
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/scipy/sparse/linalg/isolve/__init__.py", line 6, in <module>
from .iterative import *
File "/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/scipy/sparse/linalg/isolve/iterative.py", line 7, in <module>
from . import _iterative
ImportError: dlopen(/Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/scipy/sparse/linalg/isolve/_iterative.so, 2): Library not loaded: @rpath/./libgfortran.3.dylib
Referenced from: /Users/Peter/git/dataSandbox/flaskApps/sfSalary/venv/lib/python2.7/site-packages/scipy/sparse/linalg/isolve/_iterative.so
Reason: image not found
编辑：这是使用 sklearn 托管 Heroku 应用程序的一些故障排除。
我强烈建议不要为 NumPy/SciPy/Scikit-learn 和其他包含编译代码的包使用虚拟环境。虚拟环境可以很好地处理纯 Python 依赖项，但对于具有 Python 外部依赖项的已编译扩展，它们可能会以意想不到的方式失败（如您所见）。
如果你想用不同版本的 Python 包管理多个环境，包括编译的扩展，最好的工具可能是conda，特别是conda environment。
有了它，您可以运行以下命令：
$ conda create -n myenv python=3.4 numpy scipy scikit-learn
$ source activate myenv
(myenv) $ python
Python 3.4.3
>>> import sklearn
你会很高兴去的。