我已成功安装lxml，没有任何错误，请按照以下两个步骤进行操作
第1步：当我运行“python setup.py build”时，我在屏幕上打印了以下消息，
building 'lxml.etree' extension
creating build/temp.macosx-10.6-intel-2.7
creating build/temp.macosx-10.6-intel-2.7/src
creating build/temp.macosx-10.6-intel-2.7/src/lxml
llvm-gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/usr/local/include -I/usr/local/include/libxml2 -I/Users/apple/workspace/pythonhome/misc/lxml-3.0.1/src/lxml/includes -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.etree.o -flat_namespace
src/lxml/lxml.etree.c: In function ‘__pyx_pf_4lxml_5etree_4XSLT_18__call__’:
src/lxml/lxml.etree.c:132608: warning: passing argument 1 of ‘__pyx_f_4lxml_5etree_12_XSLTContext__copy’ from incompatible pointer type
src/lxml/lxml.etree.c: In function ‘__pyx_f_4lxml_5etree__copyXSLT’:
src/lxml/lxml.etree.c:133997: warning: passing argument 1 of ‘__pyx_f_4lxml_5etree_12_XSLTContext__copy’ from incompatible pointer type
src/lxml/lxml.etree.c: In function ‘__pyx_pf_4lxml_5etree_4XSLT_18__call__’:
src/lxml/lxml.etree.c:132608: warning: passing argument 1 of ‘__pyx_f_4lxml_5etree_12_XSLTContext__copy’ from incompatible pointer type
src/lxml/lxml.etree.c: In function ‘__pyx_f_4lxml_5etree__copyXSLT’:
src/lxml/lxml.etree.c:133997: warning: passing argument 1 of ‘__pyx_f_4lxml_5etree_12_XSLTContext__copy’ from incompatible pointer type
llvm-gcc-4.2 -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.etree.o -L/usr/local/lib -lxslt -lexslt -lxml2 -lz -lm -o build/lib.macosx-10.6-intel-2.7/lxml/etree.so
building 'lxml.objectify' extension
llvm-gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/usr/local/include -I/usr/local/include/libxml2 -I/Users/apple/workspace/pythonhome/misc/lxml-3.0.1/src/lxml/includes -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.objectify.c -o build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.objectify.o -flat_namespace
llvm-gcc-4.2 -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.objectify.o -L/usr/local/lib -lxslt -lexslt -lxml2 -lz -lm -o build/lib.macosx-10.6-intel-2.7/lxml/objectify.so
第2步：执行python setup.py build成功后，我执行了python setup.py install，没有错误;这看似正常和正确。
但是当我在命令行上尝试以下操作时，发生了错误？
我在基于scapy的项目中使用它。
谢谢，伙计们！
bash-3.2$ python
Python 2.7.3 (v2.7.3:70274d53c1dd, Apr 9 2012, 20:52:43)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from lxml import etree
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml-3.0.1-py2.7-macosx-10.6-intel.egg/lxml/etree.so, 2): Symbol not found: ___xmlStructuredErrorContext
Referenced from: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml-3.0.1-py2.7-macosx-10.6-intel.egg/lxml/etree.so
Expected in: flat namespace
in /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml-3.0.1-py2.7-macosx-10.6-inte
最后我尝试了这个，但是，我在python shell中得到from lxml import etree的错误：
bash-3.2$ pip install lxml-2.3.5.tgz
Unpacking ./lxml-2.3.5.tgz
Running setup.py egg_info for package from file:///Users/apple/workspace/pythonhome/misc/lxml-2.3.5.tgz
Building lxml version 2.3.5.
Building with Cython 0.17.
Using build configuration of libxslt 1.1.27
Building against libxml2/libxslt in the following directory: /usr/local/lib
warning: no previously-included files found matching '*.py'
Installing collected packages: lxml
Running setup.py install for lxml
Building lxml version 2.3.5.
Building with Cython 0.17.
Using build configuration of libxslt 1.1.27
Building against libxml2/libxslt in the following directory: /usr/local/lib
skipping 'src/lxml/lxml.etree.c' Cython extension (up-to-date)
building 'lxml.etree' extension
llvm-gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/usr/local/include -I/usr/local/include/libxml2 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.etree.o -w -flat_namespace
llvm-gcc-4.2 -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.etree.o -L/usr/local/lib -lxslt -lexslt -lxml2 -lz -lm -o build/lib.macosx-10.6-intel-2.7/lxml/etree.so
skipping 'src/lxml/lxml.objectify.c' Cython extension (up-to-date)
building 'lxml.objectify' extension
llvm-gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/usr/local/include -I/usr/local/include/libxml2 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.objectify.c -o build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.objectify.o -w -flat_namespace
llvm-gcc-4.2 -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/src/lxml/lxml.objectify.o -L/usr/local/lib -lxslt -lexslt -lxml2 -lz -lm -o build/lib.macosx-10.6-intel-2.7/lxml/objectify.so
Successfully installed lxml
Cleaning up...
bash-3.2$ python
Python 2.7.3 (v2.7.3:70274d53c1dd, Apr 9 2012, 20:52:43)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import lxml
>>> import html
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named html
>>> from lxml import html
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/html/__init__.py", line 12, in <module>
from lxml import etree
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/etree.so, 2): Symbol not found: _exsltDateXpathCtxtRegister
Referenced from: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/etree.so
Expected in: flat namespace
in /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/etree.so