Python 2.7 sys.path中链接的python二进制文件与原始文件之间的路径顺序不同

有一个python项目是使用virtualenv部署的。下一步是构建脚本的简化版本：

virtualenv --system-site-packages runtime
source ./runtime/bin/activate
pip install -r requirements.txt --index-url=...
deactivate

构建之后，我们将在

运行时/bin/

中以一些python二进制文件结束：

[....@... project1]$ ll runtime/bin/python*
lrwxrwxrwx 1 root root    9 лис 15 13:26 runtime/bin/python -> python2.7
lrwxrwxrwx 1 root root    9 лис 15 13:26 runtime/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 4864 лис 15 13:26 runtime/bin/python2.7
-rwxr-xr-x 1 root root 2350 лис 15 13:26 runtime/bin/python-config

为方便起见，在另一个目录中有一个指向

runtime/bin/python2.7

的符号链接：

bin

；与运行时位于同一级别的

bin

目录：

[...@... project1]$ ll
total 96
drwxr-xr-x 16 root root  4096 лис 15 19:27 bin
....
drwxr-xr-x  9 root root  4096 лис 15 13:26 runtime
...

[...@... project1]$ ll bin/python
lrwxrwxrwx 1 root root 24 лис 15 19:27 bin/python -> ../runtime/bin/python2.7

下面是我从链接的和原始的二进制文件中在sys.path中看到的奇怪的东西：

[...@... project1]$ bin/python -c "import sys, pprint;pprint.pprint(sys.path)"
['',
 '/media/ephemeral0/project1/src/project1_config',
 '/media/ephemeral0/project1/src/project1.api.activities',
 '/media/ephemeral0/project1/src/project1_comments',
 '/media/ephemeral0/project1/src/project1_oauthorizer',
 '/media/ephemeral0/project1/src/project1_social',
 '/media/ephemeral0/project1/src/project1_bulk',
 '/media/ephemeral0/project1/src/project1_core',
 '/media/ephemeral0/project1/src/project1_tags',
 '/media/ephemeral0/project1/src/project1_messages',
 '/media/ephemeral0/project1/src/project1_sync',
 '/media/ephemeral0/project1/src/project1_contacts',
 '/media/ephemeral0/project1/src/project1_search',
 '/media/ephemeral0/project1/src/project1_deals',
 '/media/ephemeral0/project1/src/project1_wufoo',
 '/media/ephemeral0/project1/src/project1_mailchimp',
 '/media/ephemeral0/project1/src/project1_insights',
 '/media/ephemeral0/project1/src/project1_marketing',
 '/media/ephemeral0/project1/runtime/lib64/python27.zip',
 '/usr/lib64/python2.7/site-packages/amqp-1.4.6-py2.7.egg',
 '/usr/lib64/python2.7/site-packages/Pillow-2.6.1-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/pyrasite-2.0-py2.7.egg',
 '/usr/lib/python2.7/site-packages/pyOpenSSL-0.14-py2.7.egg',
 '/usr/lib/python2.7/site-packages/cryptography-0.7.2-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/six-1.9.0-py2.7.egg',
 '/usr/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg',
 '/usr/lib/python2.7/site-packages/pyasn1-0.1.7-py2.7.egg',
 '/usr/lib/python2.7/site-packages/cffi-0.8.6-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/pycparser-2.10-py2.7.egg',
 '/media/ephemeral0/project1/runtime/lib64/python2.7',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/plat-linux2',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/lib-tk',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/lib-old',
 '/media/ephemeral0/nimble/runtime/lib64/python2.7/lib-dynload',
 '/usr/lib64/python2.7',
 '/usr/lib/python2.7',
 '/media/ephemeral0/project1/runtime/lib/python2.7/site-packages',
 '/usr/lib64/python2.7/site-packages',
 '/usr/lib/python2.7/site-packages']


[...@... project1]$ runtime/bin/python2.7 -c "import sys, pprint;pprint.pprint(sys.path)"
['',
 '/media/ephemeral0/project1/src/project1_config',
 '/media/ephemeral0/project1/src/project1.api.activities',
 '/media/ephemeral0/project1/src/project1_comments',
 '/media/ephemeral0/project1/src/project1_oauthorizer',
 '/media/ephemeral0/project1/src/project1_social',
 '/media/ephemeral0/project1/src/project1_bulk',
 '/media/ephemeral0/project1/src/project1_core',
 '/media/ephemeral0/project1/src/project1_tags',
 '/media/ephemeral0/project1/src/project1_messages',
 '/media/ephemeral0/project1/src/project1_sync',
 '/media/ephemeral0/project1/src/project1_contacts',
 '/media/ephemeral0/project1/src/project1_search',
 '/media/ephemeral0/project1/src/project1_deals',
 '/media/ephemeral0/project1/src/project1_wufoo',
 '/media/ephemeral0/project1/src/project1_mailchimp',
 '/media/ephemeral0/project1/src/project1_insights',
 '/media/ephemeral0/project1/src/project1_marketing',
 '/media/ephemeral0/project1/runtime/lib64/python27.zip',
 '/media/ephemeral0/project1/runtime/lib64/python2.7',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/plat-linux2',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/lib-tk',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/lib-old',
 '/media/ephemeral0/project1/runtime/lib64/python2.7/lib-dynload',
 '/usr/lib64/python2.7',
 '/usr/lib/python2.7',
 '/media/ephemeral0/project1/runtime/lib/python2.7/site-packages',
 '/usr/lib64/python2.7/site-packages/amqp-1.4.6-py2.7.egg',
 '/usr/lib64/python2.7/site-packages/Pillow-2.6.1-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/pyrasite-2.0-py2.7.egg',
 '/usr/lib/python2.7/site-packages/pyOpenSSL-0.14-py2.7.egg',
 '/usr/lib/python2.7/site-packages/cryptography-0.7.2-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/six-1.9.0-py2.7.egg',
 '/usr/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg',
 '/usr/lib/python2.7/site-packages/pyasn1-0.1.7-py2.7.egg',
 '/usr/lib/python2.7/site-packages/cffi-0.8.6-py2.7-linux-x86_64.egg',
 '/usr/lib/python2.7/site-packages/pycparser-2.10-py2.7.egg',
 '/usr/lib64/python2.7/site-packages',
 '/usr/lib/python2.7/site-packages']

。。。路径的顺序不同！例如：

“/media/ephemeral0/project1/runtime/lib/python2.7/site包”的位置，

。 怎么可能呢？

bin

（symlink的位置）目录中没有

.pth

文件，我无法理解谁是罪魁祸首