python和python sys.path

Question

我已经安装了anaconda，并且不想使用系统python及其模块。

假设anaconda在独立的环境中运行python。然而，

$ which python
/home/user/anaconda/bin/python

$ python --version
Python 2.7.3

$ ~/anaconda/bin/python --version
Python 2.7.11 :: Anaconda 2.5.0 (64-bit)

如您所见，python链接到2.7.3版本的系统python，尽管which表示它指向anaconda。

$ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys;
>>> from pprint import pprint as p
>>> p(sys.path)
['',
 '/soft/python/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/mock-1.0.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/nose-1.3.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/pyparsing-2.0.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/tornado-3.2-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/python_dateutil-2.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/six-1.6.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/backports.ssl_match_hostname-3.4.0.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdfgui-1.0_r6798_20120508-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.utils-1.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdffit2-1.0_r6773_20111122-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.Structure-1.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdfgetx-1.0_r2152_20130314-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/rasterstats-0.7.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/rasterio-0.24.1-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/Shapely-1.5.9-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/snuggs-1.3.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/cligj-0.2.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/affine-1.2.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/click-4.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/progress-1.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/matplotlib-1.4.3-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/h5py-2.5.0-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages',
 '/home/user',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-linux2',
 '/usr/lib/python2.7/lib-tk',
 '/usr/lib/python2.7/lib-old',
 '/usr/lib/python2.7/lib-dynload',
 '/usr/local/lib/python2.7/dist-packages',
 '/usr/lib/python2.7/dist-packages',
 '/usr/lib/python2.7/dist-packages/PIL',
 '/usr/lib/python2.7/dist-packages/gtk-2.0',
 '/usr/lib/pymodules/python2.7']

python路径中有很多系统路径，这是很自然的。但对蟒蛇来说，

$ ~/anaconda/bin/python
Python 2.7.11 |Anaconda 2.5.0 (64-bit)| (default, Dec  6 2015, 18:08:32) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://anaconda.org
>>> 
>>> import sys
>>> from pprint import pprint as p
>>> p(sys.path)
['',
 '/soft/python/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/mock-1.0.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/nose-1.3.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/pyparsing-2.0.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/tornado-3.2-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/python_dateutil-2.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/six-1.6.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/backports.ssl_match_hostname-3.4.0.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdfgui-1.0_r6798_20120508-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.utils-1.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdffit2-1.0_r6773_20111122-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.Structure-1.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/diffpy.pdfgetx-1.0_r2152_20130314-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/rasterstats-0.7.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/rasterio-0.24.1-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/Shapely-1.5.9-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/snuggs-1.3.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/cligj-0.2.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/affine-1.2.0-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/click-4.1-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/progress-1.2-py2.7.egg',
 '/soft/python/lib/python2.7/site-packages/matplotlib-1.4.3-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages/h5py-2.5.0-py2.7-linux-x86_64.egg',
 '/soft/python/lib/python2.7/site-packages',
 '/home/user',
 '/home/user/anaconda/lib/python27.zip',
 '/home/user/anaconda/lib/python2.7',
 '/home/user/anaconda/lib/python2.7/plat-linux2',
 '/home/user/anaconda/lib/python2.7/lib-tk',
 '/home/user/anaconda/lib/python2.7/lib-old',
 '/home/user/anaconda/lib/python2.7/lib-dynload',
 '/home/user/anaconda/lib/python2.7/site-packages',
 '/home/user/anaconda/lib/python2.7/site-packages/Sphinx-1.3.5-py2.7.egg',
 '/home/user/anaconda/lib/python2.7/site-packages/cryptography-1.0.2-py2.7-linux-x86_64.egg',
 '/home/user/anaconda/lib/python2.7/site-packages/flake8-2.5.1-py2.7.egg',
 '/home/user/anaconda/lib/python2.7/site-packages/mccabe-0.3.1-py2.7.egg',
 '/home/user/anaconda/lib/python2.7/site-packages/setuptools-20.1.1-py2.7.egg']

仍然有很多的系统路径。

如果我将sys.path过滤为

sys.path = filter(lambda (x): x.startswith('/home/user/anaconda'), sys.path) -- python路径是干净的，但是会有很多ImportErrors。

我已经出口了$PYTHONPATH=。

Answer 1

1. 执行type python检查别名(或函数)。
2. 执行hash -r以更新$PATH哈希表，然后再次尝试which。

一般来说，使用type可能比使用which更好，因为前者是shell内置的，可以访问shell的路径哈希表、函数和别名。

• 如果您特别希望查找外部程序(如which所做的)，则可以使用 -p型 换句话说，它是一个更可靠的which。
• 如果要查找具有给定名称的可执行命令的所有位置，可以使用 -a型

Answer 2

如果您想使用Python3，请在基于Debian的Linus发行版上创建一个指向Python和pip的符号链接。

sudo ln -s /usr/bin/python3 /usr/bin/python
sudo ln -s /usr/bin/pip3 /usr/bin/pip

Answer 3

你设置了你的Conda环境并激活它了吗？

基本上，您需要在一个文件夹中创建一个项目，启动一个终端并设置Conda环境。

conda create -n yourenvname python=x.x anaconda

在这里，您可以为您的环境选择一个名称，并设置python版本、anaconda和该环境所需的任何其他包。然后Conda将为您安装所有这些，并创建环境。

当您需要使用环境时，只需通过以下方式激活它：

activate yourenvname

阅读更多：https://uoa-eresearch.github.io/eresearch-cookbook/recipe/2014/11/20/conda/