在Mac OS X上控制Python-设置环境和库 [英] Getting Python under control on Mac OS X - setting up environment and libraries

问题描述

在Ubuntu Linux上开始使用Python之后，现在我已经在Mac(目前是Mac OS X 10.6)上进行了大部分持续工作.不幸的是，我忽略了适当地注意如何在其中安装Python并最终导致:

After starting out with Python on Ubuntu Linux, I've now for a good while been doing most of my sustained work on the Mac, currently Mac OS X 10.6. Unfortunately I've neglected to give proper attention to how Python is installed there and ended up with:

• /usr/bin中的Python 2.6.1(Mac默认版本?)(也是2.5.4，我不确定它是怎么到达的)
通过/opt/local/bin/中的 MacPorts 安装的
• Python 2.6.5.这是我的默认设置
• 我使用pip来安装库，这些库最终会出现在某些地方(如/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/-SRSLY?)
• 否则，主要是TextMate和Git用于版本控制. Django和Google App Engine等...

• Python 2.6.1 (Mac default version?) in /usr/bin (also, 2.5.4, which I'm not sure how it got there)
• Python 2.6.5 installed via MacPorts in /opt/local/bin/. This is my default
• I use pip to install libraries, which end up in some ungodly place (something like /opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/ - SRSLY?)
• Otherwise, mostly TextMate, and Git for version control. Django and Google App Engine, etc...

现在，我准备设置2.7和3.2，但我对事情的偶然状态感到不满意.那么，您最喜欢的组织代码和库的方法是什么，又如何使Mac努力提交呢?

Now I'm preparing to set up 2.7 and 3.2, and I am unhappy with the haphazard state of things. So what are your favourite approaches to organising the code and libraries, and how have you wrestled the Mac into submission?

我想继续使用pip，但是想要更多地控制或至少了解要安装哪个版本的库并可以从何处访问:我在安装py.test时遇到了问题通过pip只能从过时的2.6.1 Python加载它，而不是从我当前的2.6.5加载. MacPorts具有python_select，但并不太有用:

I'd like to continue using pip, but would like to have more control or at least understanding of what libraries for which version are getting installed and made accessible from where: I've had problems with installing py.test via pip and only being able to load it from the obsolete 2.6.1 Python, not my current 2.6.5 one. MacPorts has python_select, but it's not overly helpful:

reason: chris$ python_select -l
Available versions:
current none python26 python26-apple

我问过的大多数Python用户不使用MacPorts，我不太喜欢，但使用的是python.org中的Mac Python.我也听说过建议系统地使用virtualenv的建议，那么，一个好的实用介绍的链接是什么?

Most Python people I've asked don't use MacPorts, which I don't much like, but the stock Mac Python from python.org. I've also heard the recommendation to use virtualenv systematically, so what is the link to a good practical introduction?

推荐答案

virutalenv是一个很好的工具，对于在大多数平台上管理多个Python实例非常有用.但是，在Mac OS X上，事情变得更加复杂，因为使用框架构建使遇到相同主版本Python的多个实例变得很普遍.我建议您先研究并熟悉如何在Mac OS X上管理框架安装，然后再研究virtualenv.

virutalenv is a great tool and is very useful for managing multiple Python instances on most platforms. On Mac OS X, though, things are more complicated because the use of framework builds makes it common to encounter multiple instances of even the same major version of Python. I suggest you first understand and be comfortable with how to manage framework installs on Mac OS X before delving into virtualenv.

"/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/-SRSLY?"

"/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/ - SRSLY?"

是的，这是Python Mac OS X框架版本中的默认位置.在Mac OS X上，大多数Python发行商都使用框架构建，每个发行人通常使用不同的根目录，因为这样可以更轻松地支持多个版本并为特定的Python保留所有站点包的安装.实例一起放在一个地方.

Yes, that's the default location within a Python Mac OS X framework build. Most distributors of Python on Mac OS X use a framework build, each generally using a different root, because it makes it simpler to support multiple versions and to keep all the site packages installed for a particular Python instance together in one place.

对于Mac OS X 10.6，Apple提供了Python 2.6(植根于/System/Library/Frameworks/Python.framework并符号链接到/usr/bin/python2.6)和Python 2.5(与Mac OS X 10.5兼容-即您会看到). python.org Mac OS X安装程序会安装到/Library/Frameworks/Python.framework. MacPorts使用/opt/local/Library/Frameworks/Python.framework.

For Mac OS X 10.6, Apple supplies a Python 2.6 (rooted at /System/Library/Frameworks/Python.framework and symlinked to /usr/bin/python2.6) as well as a Python 2.5 (for compatibility with Mac OS X 10.5 - that's the /usr/bin/python2.5 you see). The python.org Mac OS X installers install to /Library/Frameworks/Python.framework. MacPorts uses /opt/local/Library/Frameworks/Python.framework.

框架包括bin目录(在框架中的../Versions/x.x/bin)；这通常是安装程序包脚本的默认位置.也是指向解释器二进制文件的符号链接所在的地方.

The frameworks include a bin directory (at ../Versions/x.x/bin in the framework); this is normally the default location where package scripts will be installed. It's also where symlinks to the interpreter binaries are placed.

这里是一个安装了多个Python版本的python.org样式框架:

Here's a look at a python.org-style framework with multiple versions of Python installed:

$ cd /Library/Frameworks/Python.framework/Versions/
$ ls -l
total 8
drwxrwxr-x  8 root  admin  340 Dec 23  2008 2.5/
drwxrwxr-x  8 root  admin  340 Aug 10 21:42 2.6/
drwxrwxr-x  8 root  admin  340 Jul  3 12:24 2.7/
drwxrwxr-x  7 root  admin  306 Mar 23 17:42 3.1/
drwxrwxr-x  7 root  admin  306 Aug 10 22:14 3.2/
lrwxr-xr-x  1 root  admin    3 Aug 10 21:47 Current@ -> 2.6
$ cd 2.6
$ ls -l
total 7776
lrwxr-xr-x  1 root  admin       17 Aug 10 21:47 Headers@ -> include/python2.6
drwxrwxr-x  3 root  admin      102 Aug 10 21:42 Mac/
-r-xrwxr-x  1 root  admin  3973552 Aug 10 21:41 Python*
drwxrwxr-x  4 root  admin      170 Aug 10 21:48 Resources/
drwxrwxr-x  2 root  admin      578 Aug 12 15:19 bin/
drwxrwxr-x  3 root  admin      102 Aug 10 21:42 include/
drwxrwxr-x  3 root  admin      646 Aug 10 21:43 lib/
drwxrwxr-x  3 root  admin      102 Aug 10 21:41 share/
$ ls -l bin
total 264
-rwxrwxr-x  1 root  admin    150 Aug 10 21:41 2to3*
-rwxr-xr-x  1 nad   admin    360 Aug 12 15:19 easy_install*
-rwxr-xr-x  1 nad   admin    368 Aug 12 15:19 easy_install-2.6*
lrwxr-xr-x  1 root  admin      7 Aug 10 21:47 idle@ -> idle2.6
-rwxrwxr-x  1 root  admin    138 Aug 10 21:41 idle2.6*
lrwxr-xr-x  1 root  admin      8 Aug 10 21:47 pydoc@ -> pydoc2.6
-rwxrwxr-x  1 root  admin    123 Aug 10 21:41 pydoc2.6*
lrwxr-xr-x  1 root  admin      9 Aug 10 21:47 python@ -> python2.6
lrwxr-xr-x  1 root  admin     16 Aug 10 21:47 python-config@ -> python2.6-config
-rwxrwxr-x  1 root  admin  29584 Aug 10 21:43 python2.6*
-rwxrwxr-x  1 root  admin   1463 Aug 10 21:42 python2.6-config*
lrwxr-xr-x  1 root  admin     10 Aug 10 21:47 pythonw@ -> pythonw2.6
-rwxrwxr-x  1 root  admin  29584 Aug 10 21:43 pythonw2.6*
lrwxr-xr-x  1 root  admin     11 Aug 10 21:47 smtpd.py@ -> smtpd2.6.py
-rwxrwxr-x  1 root  admin  18272 Aug 10 21:41 smtpd2.6.py*

这是MacPorts bin，其中包括许多其他站点软件包:

Here's a MacPorts bin including a number of additional site packages:

$ cd /opt/local/Library/Frameworks/Python.framework/Versions/2.6
$ ls -l bin
total 952
-rwxr-xr-x  2 root  wheel    160 Jul 15 01:56 2to3*
-rwxr-xr-x  2 root  wheel   1541 Jun  8 19:59 apirst2html.py*
-rwxr-xr-x  2 root  wheel    363 Oct  5  2009 bdist_mpkg*
[...]
-rwxr-xr-x  2 root  wheel    211 Jun  2 12:45 django-admin.py*
-rwxr-xr-x  2 root  wheel    410 Jul 15 17:30 easy_install*
-rwxr-xr-x  2 root  wheel    418 Jul 15 17:30 easy_install-2.6*
[...]
-rwxr-xr-x  2 root  wheel    368 Jun 24 02:00 pip*
-rwxr-xr-x  1 root  wheel    342 Sep 18  2009 pkginfo*
[...]
lrwxr-xr-x  1 root  wheel      9 Jul 15 01:58 python@ -> python2.6
lrwxr-xr-x  1 root  wheel     16 Jul 15 01:58 python-config@ -> python2.6-config
-rwxr-xr-x  2 root  wheel  24932 Jul 15 01:57 python2.6*
-rwxr-xr-x  2 root  wheel   1473 Jul 15 01:57 python2.6-config*
[...]

如果使用python.org安装程序或MacPorts安装2.7或3.1 Python，它们全部植根于/Library/Frameworks或/opt/local/Library/Frameworks，并且可以与其他版本愉快地共存.要成功使用框架安装，您需要管理shell PATH.特别是，您应确保要使用的Python的框架bin目录位于PATH上.因此，对于MacPorts，在~/.bash_profile中是这样的:

If you install 2.7 or 3.1 Pythons using python.org installers or MacPorts, they are all rooted under /Library/Frameworks or /opt/local/Library/Frameworks and will happily co-exist with other versions. To successfully use framework installs, you need to manage your shell PATH. In particular, you should ensure that the framework bin directory of the Python(s) you want to use are on your PATH. So for MacPorts, something like this in ~/.bash_profile:

export PATH="/opt/local/Library/Frameworks/Python.framework/Versions/2.6/bin:/opt/local/bin:$PATH

或python.org安装程序:

or for the python.org installers:

export PATH="/Library/Frameworks/Python.framework/Versions/2.6/bin:$PATH

此外，通常，您需要为使用的每个Python实例安装一个单独版本的喜爱的Python软件包管理插件(例如pip或Distribute或setuptools中的easy_install命令).每个都安装到默认脚本目录(即框架bin目录)中. MacPorts在安装其软件包的版本(sudo port install py26-pip或sudo port install py31-distribute)时会自动进行处理.请注意，Apple在/usr/bin中为其Python提供了一组easy_install链接，并且它们将软件包安装到/Library/Python.您需要确保使用适用于您的Python实例的easy_install或pip.确保实例的框架bin目录在PATH中首先位于该位置.

In addition, generally you need to install a separate version of your favorite Python package management add-ons (like pip or the easy_install command from Distribute or setuptools) for each Python instance you use. Each one is installed into the default script directory (i.e. the framework bin directory). MacPorts takes care of that automatically when you install its version of the package (sudo port install py26-pip or sudo port install py31-distribute). Note that Apple supplies a set of easy_install links in /usr/bin for its Pythons and they install packages to /Library/Python. You need to make sure you use the easy_install or pip appropriate for your instance of Python. Making sure the instance's framework bin directory is first in the PATH ensures that.

请注意，如果您使用MacPorts，则可以使用其python_select命令来管理/opt/local/bin/python指向哪个Python实例.然后，如果/opt/local/bin出现在PATH列表中的位置早于其他带有python的目录，它将决定哪个是默认的python.但是您确实需要通过添加框架bin目录来管理PATH，因此python_select通常并没有那么有用.

Note, if you use MacPorts you can use its python_select command to manage which Python instance is pointed to by /opt/local/bin/python. Then if /opt/local/bin appears earlier in your PATH list than other directories with a python it will govern which is your default python. But you really need to manage the PATH by adding the framework bin directory so python_select is generally not all that useful.

使用MacPorts(或类似的基础广泛的发行商)的另一个积极方面是，它提供了许多流行的Python程序包，包括，这些临时程序处理了构建和链接到第三方C库时偶尔出现的混乱细节， Mac  OS  X随附.例如，由于MySQL客户端库和libjpeg，MySQLdb和PIL软件包在Mac OS X上经常成为绊脚石，但是MacPorts使得正确处理一切变得容易得多.但是您可以选择直接使用MacPorts(sudo port py26-pil)或通过pip(sudo pip install pil)或easy_install直接安装，也可以下载源代码并自己进行安装(sudo python setup.py ...).而且由于所有这些方法都是使用Python的Distutils来完成肮脏的工作，因此，对于给定的Python实例，所有这些方法通常都会最终将软件包的文件安装在同一位置.

Another positive aspect of using MacPorts (or similar broad-based distributor) is that it makes available many popular Python packages including handling the occasional messy details of building and linking to 3rd-party C libraries not shipped with Mac OS X. For example, the MySQLdb and PIL packages are frequent stumbling blocks on Mac OS X because of the MySQL client libraries and libjpeg, but MacPorts makes it much easier to get everything right. But you do have the choice to install things directly using MacPorts (sudo port py26-pil) or via pip (sudo pip install pil) or easy_install, or you can download the source, and do it yourself (sudo python setup.py ...). And because all of them under the covers use Python's Distutils to do the dirty work, all of these methods will generally end up installing a package's files in the same place for a given Python instance.

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