我一直习惯使用 setuptools 来安装 python 的程序库，因为 easy_install 实在是太简单实用了。但因为公司的网络环境比较严格，把具有登陆功能的 pypi.python.org 域名给禁用了，开放的是 c.pypi.python.org 镜像，使用 setuptools 安装 python 程序库的时候有些包下载不了，如下：
- xxx@ubuntu:~# easy_install -i http://c.pypi.python.org/simple -U lxml
- Searching for lxml
- Reading http://c.pypi.python.org/simple/lxml/
- Reading http://codespeak.net/lxml
- Reading http://lxml.de/
- Best match: lxml 2.3.3
- Downloading http://pypi.python.org/packages/source/l/lxml/lxml-2.3.3.tar.gz
- error: Can't download http://pypi.python.org/packages/source/l/lxml/lxml-2.3.3.tar.gz: 403 Forbidden
后来发现是其尝试机制有问题，其实 lxml-2.3.3.tar.gz 在镜像站中本身就有，只是 easy_install 尝试了一次下载链接不成功后就放弃了。太不够执着了！我先定位到尝试下载的地方，然后直接修改了其源码，让它遇到下载不成功后再多试试其它的 URL，就解决了问题：
- xxx@ubuntu:~# easy_install -i http://c.pypi.python.org/simple -U lxml
- Searching for lxml
- Reading http://c.pypi.python.org/simple/lxml/
- Reading http://codespeak.net/lxml
- Reading http://lxml.de/
- Best match: lxml 2.3.3
- Downloading http://pypi.python.org/packages/source/l/lxml/lxml-2.3.3.tar.gz
- Can't download http://pypi.python.org/packages/source/l/lxml/lxml-2.3.3.tar.gz: 403 Forbidden.
- Best match: lxml 2.3.3
- Downloading http://c.pypi.python.org/packages/source/l/lxml/lxml-2.3.3.tar.gz#md5=a7825793c69d004f388ec6600bad7a6f
- Processing lxml-2.3.3.tar.gz
- Running lxml-2.3.3/setup.py -q bdist_egg --dist-dir /tmp/easy_install-0g1ftW/lxml-2.3.3/egg-dist-tmp-T6eTHt
- Building lxml version 2.3.3.
- Building with Cython 0.15.1.
- Using build configuration of libxslt 1.1.26
- Building against libxml2/libxslt in the following directory: /usr/lib
- Adding lxml 2.3.3 to easy-install.pth file
- Installed /usr/local/lib/python2.6/dist-packages/lxml-2.3.3-py2.6-linux-x86_64.egg
- Processing dependencies for lxml
- Finished processing dependencies for lxml
补丁如下：
- Index: package_index.py
- ===================================================================
- --- package_index.py (revision 124)
- +++ package_index.py (working copy)
- @@ -445,10 +445,14 @@
- continue
- if dist in req and (dist.precedence<=SOURCE_DIST or not source):
- - return dist
- + self.info("Best match: %s", dist)
- + try:
- + return dist.clone(location=self.download(dist.location, tmpdir))
- + except DistutilsError, e:
- + self.info(str(e))
- + continue
- -
- if force_scan:
- self.prescan()
- self.find_packages(requirement)
- @@ -471,8 +475,7 @@
- (source and "a source distribution of " or ""),
- requirement,
- )
- - self.info("Best match: %s", dist)
- - return dist.clone(location=self.download(dist.location, tmpdir))
- + return dist
- def fetch(self, requirement, tmpdir, force_scan=False, source=False):
后来考虑到很多朋友即使公司没设黑名单，但也可能会有域名无法访问，打 patch 也麻烦，所以我就自己打包了一个 patch 后的 setuptools，大家可以在这里（http://abu-rpc.googlecode.com/files/setuptools-0.6c11-lai-patched.tar.gz）下载。
