PYTHONPATH 环境变量之前的路径中的鸡蛋 [英] Eggs in path before PYTHONPATH environment variable

问题描述

如果我从 easy_install 安装了软件包，则在 PYTHONPATH 变量中的项目之前，将鸡蛋添加到 sys.path 中.

例如，如果我在当前目录中安装了一个名为 foo 的 egg 包以及一个名为 foo 的包，然后执行以下操作:

PYTHONPATH="."Python>>>进口富

这将使用 foo 的 egg 版本而不是本地目录.检查 sys.path 显示鸡蛋位于 PYTHONPATH 的之前 项.这似乎坏了.有没有办法覆盖这种行为?

解决方案

不幸的是，这是通过 setuptools/command/easy_install.py 深处的硬编码模板完成的.您可以使用编辑过的模板创建修补过的 setuptools，但我没有找到从外部扩展 easy_install 的干净方法.

easy_install 每次运行时都会重新生成文件easy_install.pth.这是一个可以在 easy_install 之后运行的快速脚本，用于从 easy_install.pth 中删除页眉和页脚.您可以创建一个包装 shell 脚本以在 easy_install 之后立即运行它:

#!/usr/bin/env python导入系统路径 = sys.argv[1]行 = 打开(路径，'rb').readlines()如果行和行 [0] 中的导入系统":open(path, 'wb').write(''.join(lines[1:-1]) + '\n')

示例:

% easy_install gdata% PYTHONPATH=xyz python -c 'import sys;打印 sys.path[:2]'['', '/Users/pat/virt/lib/python2.6/site-packages/gdata-2.0.14-py2.6.egg']% ./fix_path ~/virt/lib/python2.6/site-packages/easy_install.pth% PYTHONPATH=xyz python -c 'import sys;打印 sys.path[:2]'['', '/Users/pat/xyz']

为了更清楚，这里是easy-install.pth的格式:

import sys;sys.__plen = len(sys.path)./gdata-2.0.14-py2.6.egg导入系统；new=sys.path[sys.__plen:];del sys.path[sys.__plen:];p=getattr(sys,'__egginsert',0);sys.path[p:p]=new;sys.__egginsert = p+len(new)

这两行 import sys 是导致鸡蛋出现在路径开头的罪魁祸首.我的脚本只是删除了那些 sys.path-munging 行.

If I have packages installed from easy_install, the eggs are prepended to sys.path before the items in the PYTHONPATH variable.

For example, if I have an egg package called foo installed as well as a package called foo in the current directory, and then do this:

PYTHONPATH="." python
>>> import foo

This will use the egg version of foo instead of the local directory. Inspecting sys.path shows that eggs are placed before items from PYTHONPATH. This seems broken. Is there any way to override this behavior?

解决方案

Unfortunately this is done with a hard-coded template deep inside setuptools/command/easy_install.py. You could create a patched setuptools with an edited template, but I've found no clean way to extend easy_install from the outside.

Each time easy_install runs it will regenerate the file easy_install.pth. Here is a quick script which you can run after easy_install, to remove the header and footer from easy_install.pth. You could create a wrapper shell script to run this immediately after easy_install:

#!/usr/bin/env python
import sys
path = sys.argv[1]
lines = open(path, 'rb').readlines()
if lines and 'import sys' in lines[0]:
    open(path, 'wb').write(''.join(lines[1:-1]) + '\n')

Example:

% easy_install gdata
% PYTHONPATH=xyz python -c 'import sys; print sys.path[:2]'
['', '/Users/pat/virt/lib/python2.6/site-packages/gdata-2.0.14-py2.6.egg']

% ./fix_path ~/virt/lib/python2.6/site-packages/easy_install.pth
% PYTHONPATH=xyz python -c 'import sys; print sys.path[:2]'
['', '/Users/pat/xyz']

For more clarification, here is the format of easy-install.pth:

import sys; sys.__plen = len(sys.path)
./gdata-2.0.14-py2.6.egg
import sys; new=sys.path[sys.__plen:]; del sys.path[sys.__plen:]; p=getattr(sys,'__egginsert',0); sys.path[p:p]=new; sys.__egginsert = p+len(new)

The two import sys lines are the culprit causing the eggs to appear at the start of the path. My script just removes those sys.path-munging lines.

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