python如何加载sys.path中的所有值？

Posted 2023-02-24

【中文标题】python如何加载sys.path中的所有值？

【英文标题】：How does python load all the values in sys.path?

【发布时间】：2011-05-23 01:27:01

【问题描述】：

我是一名 Python 初学者，我刚开始使用自己的 Python 脚本和项目，例如 django。

我使用 Ubuntu 并将我的 PYTHONPATH 设置为

export PYTHONPATH=/usr/lib/python2.6:~/Projects/mypython 

当我遇到 python 解释器时

import sys
print sys.path

我可以看到

['', '/usr/bin', '/usr/local/lib/python2.6/dist-packages/ropemode-0.1_rc2-py2.6.egg', '/usr/local/lib/ python2.6/dist-packages/rope-0.9.3-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/ropevim-0.3_rc-py2.6.egg', ' /usr/lib/python2.6'、'/home/jaume/Projects/mypython'、'/usr/lib/python2.6/plat-linux2'、'/usr/lib/python2.6/lib-tk' , '/usr/lib/python2.6/lib-old', '/usr/lib/python2.6/lib-dynload', '/usr/local/lib/python2.6/dist-packages', '/ usr/lib/python2.6/dist-packages'，'/usr/lib/python2.6/dist-packages/PIL'，'/usr/lib/python2.6/dist-packages/gst-0.10'，' /usr/lib/pymodules/python2.6', '/usr/lib/python2.6/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.6/gtk-2.0', '/ usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode', '/usr/lib/pymodules/python2.6/IPython/Extensions', u'/home/jaume/.ipython']

python 如何加载所有非 PYTHONPATH 路径？有没有索引？此外，我的 django 安装在 /usr/lib/pymodules 中，即使它不在 sys.path 列表中，它也会运行。

非常感谢。

【问题讨论】：

要了解 django 是如何加载的，请检查路径：>>> import django >>> django.__path__ ['/usr/local/lib/python2.6/dist-packages/django']

我只能看到 ['django']。也许是因为它是从 'apt-get' 安装的

【参考方案1】：

阅读：http://docs.python.org/library/site.html#module-site

【参考方案2】：

这是我计算机上的 Python 解释器（与您的设置类似但不一样）在开始运行我提供的代码之前打开的每个文件的列表：

$ strace -eopen python -c 1 2>&1 | grep -ve '-1 E'
open("/etc/ld.so.cache", O_RDONLY)      = 3
open("/lib/libpthread.so.0", O_RDONLY)  = 3
open("/lib/libdl.so.2", O_RDONLY)       = 3
open("/lib/libutil.so.1", O_RDONLY)     = 3
open("/usr/lib/libssl.so.0.9.8", O_RDONLY) = 3
open("/usr/lib/libcrypto.so.0.9.8", O_RDONLY) = 3
open("/usr/lib/libz.so.1", O_RDONLY)    = 3
open("/lib/libm.so.6", O_RDONLY)        = 3
open("/lib/libc.so.6", O_RDONLY)        = 3
open("/proc/meminfo", O_RDONLY)         = 3
open("/usr/lib/python2.6/site.py", O_RDONLY) = 3
open("/usr/lib/python2.6/site.pyc", O_RDONLY) = 4
open("/usr/lib/python2.6/os.py", O_RDONLY) = 4
open("/usr/lib/python2.6/os.pyc", O_RDONLY) = 5
open("/usr/lib/python2.6/posixpath.py", O_RDONLY) = 5
open("/usr/lib/python2.6/posixpath.pyc", O_RDONLY) = 6
open("/usr/lib/python2.6/stat.py", O_RDONLY) = 6
open("/usr/lib/python2.6/stat.pyc", O_RDONLY) = 7
open("/usr/lib/python2.6/genericpath.py", O_RDONLY) = 6
open("/usr/lib/python2.6/genericpath.pyc", O_RDONLY) = 7
open("/usr/lib/python2.6/warnings.py", O_RDONLY) = 6
open("/usr/lib/python2.6/warnings.pyc", O_RDONLY) = 7
open("/usr/lib/python2.6/linecache.py", O_RDONLY) = 7
open("/usr/lib/python2.6/linecache.pyc", O_RDONLY) = 8
open("/usr/lib/python2.6/types.py", O_RDONLY) = 7
open("/usr/lib/python2.6/types.pyc", O_RDONLY) = 8
open("/usr/lib/python2.6/UserDict.py", O_RDONLY) = 5
open("/usr/lib/python2.6/UserDict.pyc", O_RDONLY) = 6
open("/usr/lib/python2.6/_abcoll.py", O_RDONLY) = 6
open("/usr/lib/python2.6/_abcoll.pyc", O_RDONLY) = 7
open("/usr/lib/python2.6/abc.py", O_RDONLY) = 7
open("/usr/lib/python2.6/abc.pyc", O_RDONLY) = 8
open("/usr/lib/python2.6/copy_reg.py", O_RDONLY) = 5
open("/usr/lib/python2.6/copy_reg.pyc", O_RDONLY) = 6
open("/usr/local/lib/python2.6/dist-packages", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 4
open("/usr/lib/python2.6/dist-packages", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 4
open("/usr/lib/python2.6/dist-packages/PIL.pth", O_RDONLY) = 4
open("/usr/lib/python2.6/dist-packages/pygst.pth", O_RDONLY) = 4
open("/usr/lib/python2.6/dist-packages/python-support.pth", O_RDONLY) = 4
open("/usr/lib/python2.6/dist-packages/wx.pth", O_RDONLY) = 4
open("/usr/lib/python2.6/dist-packages/zope.interface-3.5.3-nspkg.pth", O_RDONLY) = 4
open("/usr/lib/python2.6/sitecustomize.py", O_RDONLY) = 4
open("/usr/lib/python2.6/sitecustomize.pyc", O_RDONLY) = 5
open("/usr/lib/locale/locale-archive", O_RDONLY) = 3
open("/usr/lib/python2.6/encodings/__init__.py", O_RDONLY) = 3
open("/usr/lib/python2.6/encodings/__init__.pyc", O_RDONLY) = 4
open("/usr/lib/python2.6/codecs.py", O_RDONLY) = 4
open("/usr/lib/python2.6/codecs.pyc", O_RDONLY) = 5
open("/usr/lib/python2.6/encodings/aliases.py", O_RDONLY) = 4
open("/usr/lib/python2.6/encodings/aliases.pyc", O_RDONLY) = 5
open("/usr/lib/python2.6/encodings/utf_8.py", O_RDONLY) = 3
open("/usr/lib/python2.6/encodings/utf_8.pyc", O_RDONLY) = 4

所有这些都可能（至少可能）对 sys.path 产生影响。然而，site.py 之前的东西极不可能出现（这些都是不特定于 Python 的操作系统库和接口）。我建议您仔细查看site.py、sitecustomize.py 和各种.pth 文件（您的.pth 文件列表将与我的不同；这很正常）。