通过 pip 成功安装 lxml 后，在 python 命令行中执行“from lxml import etree”时出现错误

    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 "", line 1, in 
    ImportError: No module named html
    >>> from lxml import html
    Traceback (most recent call last):
      File "", line 1, in 
      File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/html/__init__.py", line 12, in 
        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

  

对于旧版本 lxml2.3.4 再次出现相同的错误

    bash-3.2$ pip install lxml-2.3.4.tgz 
    Unpacking ./lxml-2.3.4.tgz
      Running setup.py egg_info for package from file:///Users/apple/workspace/pythonhome/misc/lxml-2.3.4.tgz
        Building lxml version 2.3.4.
        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 2.3.4.
        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 os
    >>> import lxml
    >>> from lxml import etree
    Traceback (most recent call last):
      File "", line 1, in 
    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

  

也可以看看将 lxml.etree 导入 python 时出现错误 https://stackoverflow.com/questions/13355984/get-errors-when-import-lxml-etree-to-python

我认为这里的关键错误是：

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/etree.so, 2): Symbol not found: _exsltDateXpathCtxtRegister

I found lxml 开发列表中另一个有同样问题的人 http://permalink.gmane.org/gmane.comp.python.lxml.devel/6028.

他们的建议：

您可能需要检查您的 libxml/libxslt 库。确保您拥有所需的版本lxml安装说明 http://lxml.de/installation.html

从跑步开始

ldd /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/lxml/etree.so

这将显示您是否有任何未解析的共享库。您可能需要安装/更新一些软件包。

检查上面链接的线程以获取更多故障排除提示。