我在python项目虚拟环境中尝试安装软件包时遇到错误。但是，当我尝试在虚拟环境之外通过相同的命令（pip3安装翻译）安装相同的软件包时，就可以了。
点19.0.3Python 3.8.2
Using cached https://files.pythonhosted.org/packages/85/b2/2ea329a07bbc0c7227eef84ca89ffd6895e7ec237d6c0b26574d56103e53/translate-3.5.0-py2.py3-none-any.whl
[已经满足的要求：e：\ testproject \ venv \ lib \ site-packages中的Tox（来自翻译）（3.14.6）已满足要求：在e：\ testproject \ venv \ lib \ site-packages中进行预提交（来自翻译）（2.3.0）已满足要求：单击e：\ testproject \ venv \ lib \ site-packages（来自翻译）（7.1.1）收集lxml（来自translate）使用缓存的https://files.pythonhosted.org/packages/39/2b/0a66d5436f237aff76b91e68b4d8c041d145ad0a2cdeefe2c42f76ba2857/lxml-4.5.0.tar.gz已经满足要求：e：\ testproject \ venv \ lib \ site-packages中的请求（来自translate）（2.23.0）已经满足要求：e：\ testproject \ venv \ lib \ site-packages中的toml> = 0.9.4（tox-> translate）（0.10.0）已经满足要求：e：\ testproject \ venv \ lib \ site-packages中的filelock <4，> = 3.0.0（tox-> translate）（3.0.12）已经满足的要求：colorama> = 0.4.1; platform_system ==“ Windows” in e：\ testproject \ venv \ lib \ site-packages（来自tox-> translate）（0.4.3）已经满足要求：virtualenv！= 20.0.0，！= 20.0.1，！= 20.0.2，！= 20.0.3，！= 20.0.4，！= 20.0.5，！= 20.0.6，！= 20.0 e：\ testproject \ venv \ lib \ site-packages中的.7，> = 16.0.0（来自tox-> translate）（20.0.18）已经满足要求：e：\ testproject \ venv \ lib \ site-packages中的Packaging> = 14（来自tox-> translate）（20.3）已经满足的要求：e：\ testproject \ venv \ lib \ site-packages中的六个<2，> = 1.14.0（tox-> translate）（1.14.0）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的py <2，> = 1.4.17（tox-> translate）（1.8.1）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的pluggy <1，> = 0.12.0（tox-> translate）（0.13.1）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的cfgv> = 2.0.0（来自pre-commit-> translate）（3.1.0）已满足要求：在e：\ testproject \ venv \ lib \ site-packages中标识> = 1.0.0（来自pre-commit-> translate）（1.4.15）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的pyyaml> = 5.1（来自pre-commit-> translate）（5.3.1）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的nodeenv> = 0.11.1（来自pre-commit-> translate）（1.3.5）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的chardet <4，> = 3.0.2（来自请求->转换）（3.0.4）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的certifi> = 2017.4.17（来自request-> translate）（2020.4.5.1）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的urllib3！= 1.25.0，！= 1.25.1，<1.26，> = 1.21.1（来自请求->翻译）（1.25.9）已经满足要求：e：\ testproject \ venv \ lib \ site-packages中的idna <3，> = 2.5（来自请求->翻译）（2.9）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的appdirs <2，> = 1.4.3（来自virtualenv！= 20.0.0，！= 20.0.1，！= 20.0.2，！= 20.0 .3，！= 20.0.4，！= 20.0.5，！= 20.0.6，！= 20.0.7，> = 16.0.0-> tox-> translate）（1.4.3）已满足要求：e：\ testproject \ venv \ lib \ site-packages中的distlib <1，> = 0.3.0（来自virtualenv！= 20.0.0，！= 20.0.1，！= 20.0.2，！= 20.0 .3，！= 20.0.4，！= 20.0.5，！= 20.0.6，！= 20.0.7，> = 16.0.0-> tox-> translate）（0.3.0）已经满足的要求：在e：\ testproject \ venv \ lib \ site-packages中进行pyparsing> = 2.0.2（来自Packaging> = 14-> tox-> translate）（2.4.7）安装收集的软件包：lxml，翻译正在为lxml运行setup.py install ...错误从命令E：\ TestProject \ venv \ Scripts \ python.exe -u -c“ import setuptools，tokenize; file ='C：\ Users \ rabby \ AppData \ Local \ Temp \ pip-install- muzepxbu \ lxml \ setup.py'; f = getattr（tokenize，'open'，open）（file）; code = f.read（）。replace（'\ r \ n'，'\ n' ）; f.close（）; exec（compile（code，file，'exec'）））“安装--record C：\ Users \ rabby \ AppData \ Local \ Temp \ pip-record-0023ymbj \ install -record.txt-单一版本-外部管理-编译--install-headers E：\ TestProject \ venv \ include \ site \ python3.8 \ lxml：构建lxml版本4.5.0。没有Cython的建筑物。错误：b“'xslt-config'无法识别为内部或外部命令，\ r \ noperable程序或批处理文件。\ r \ n”**确保已安装libxml2和libxslt的开发包**
Using build configuration of libxslt
running install
running build
running build_py
creating build
creating build\lib.win32-3.8
creating build\lib.win32-3.8\lxml
copying src\lxml\builder.py -> build\lib.win32-3.8\lxml
copying src\lxml\cssselect.py -> build\lib.win32-3.8\lxml
copying src\lxml\doctestcompare.py -> build\lib.win32-3.8\lxml
copying src\lxml\ElementInclude.py -> build\lib.win32-3.8\lxml
copying src\lxml\pyclasslookup.py -> build\lib.win32-3.8\lxml
copying src\lxml\sax.py -> build\lib.win32-3.8\lxml
copying src\lxml\usedoctest.py -> build\lib.win32-3.8\lxml
copying src\lxml\_elementpath.py -> build\lib.win32-3.8\lxml
copying src\lxml\__init__.py -> build\lib.win32-3.8\lxml
creating build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\__init__.py -> build\lib.win32-3.8\lxml\includes
creating build\lib.win32-3.8\lxml\html
copying src\lxml\html\builder.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\clean.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\defs.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\diff.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\ElementSoup.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\formfill.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\html5parser.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\soupparser.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\usedoctest.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\_diffcommand.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\_html5builder.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\_setmixin.py -> build\lib.win32-3.8\lxml\html
copying src\lxml\html\__init__.py -> build\lib.win32-3.8\lxml\html
creating build\lib.win32-3.8\lxml\isoschematron
copying src\lxml\isoschematron\__init__.py -> build\lib.win32-3.8\lxml\isoschematron
copying src\lxml\etree.h -> build\lib.win32-3.8\lxml
copying src\lxml\etree_api.h -> build\lib.win32-3.8\lxml
copying src\lxml\lxml.etree.h -> build\lib.win32-3.8\lxml
copying src\lxml\lxml.etree_api.h -> build\lib.win32-3.8\lxml
copying src\lxml\includes\c14n.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\config.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\dtdvalid.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\etreepublic.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\htmlparser.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\relaxng.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\schematron.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\tree.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\uri.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xinclude.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xmlerror.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xmlparser.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xmlschema.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xpath.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\xslt.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\__init__.pxd -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\etree_defs.h -> build\lib.win32-3.8\lxml\includes
copying src\lxml\includes\lxml-version.h -> build\lib.win32-3.8\lxml\includes
creating build\lib.win32-3.8\lxml\isoschematron\resources
creating build\lib.win32-3.8\lxml\isoschematron\resources\rng
copying src\lxml\isoschematron\resources\rng\iso-schematron.rng -> build\lib.win32-3.8\lxml\isoschematron\resources\rng
creating build\lib.win32-3.8\lxml\isoschematron\resources\xsl
copying src\lxml\isoschematron\resources\xsl\RNG2Schtrn.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl
copying src\lxml\isoschematron\resources\xsl\XSD2Schtrn.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl
creating build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\iso_abstract_expand.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\iso_dsdl_include.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\iso_schematron_message.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\iso_schematron_skeleton_for_xslt1.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\iso_svrl_for_xslt1.xsl -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
copying src\lxml\isoschematron\resources\xsl\iso-schematron-xslt1\readme.txt -> build\lib.win32-3.8\lxml\isoschematron\resources\xsl\iso-schematron-xslt1
running build_ext
building 'lxml.etree' extension
creating build\temp.win32-3.8
creating build\temp.win32-3.8\Release
creating build\temp.win32-3.8\Release\src
creating build\temp.win32-3.8\Release\src\lxml
C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.16.27023\bin\HostX86\x86\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -DCYTHON_CLINE_IN_TRACEBACK=0 -Isrc -Isrc\lxml\includes -IE:\TestProject\venv\include -IC:\Users\rabby\AppData\Local\Programs\Python\Python38-32\include -IC:\Users\rabby\AppData\Local\Programs\Python\Python38-32\include "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.16.27023\include" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\winrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\cppwinrt" /Tcsrc\lxml\etree.c /Fobuild\temp.win32-3.8\Release\src\lxml\etree.obj -w
cl : Command line warning D9025 : overriding '/W3' with '/w'
etree.c
c:\users\rabby\appdata\local\temp\pip-install-muzepxbu\lxml\src\lxml\includes/etree_defs.h(14): fatal error C1083: Cannot open include file: 'libxml/xmlversion.h': No such file or directory
Compile failed: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\BuildTools\\VC\\Tools\\MSVC\\14.16.27023\\bin\\HostX86\\x86\\cl.exe' failed with exit status 2
creating Users
creating Users\rabby
creating Users\rabby\AppData
creating Users\rabby\AppData\Local
creating Users\rabby\AppData\Local\Temp
C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.16.27023\bin\HostX86\x86\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -I/usr/include/libxml2 "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.16.27023\include" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\winrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\cppwinrt" /TcC:\Users\rabby\AppData\Local\Temp\xmlXPathInitt0q8ob77.c /FoUsers\rabby\AppData\Local\Temp\xmlXPathInitt0q8ob77.obj
xmlXPathInitt0q8ob77.c
C:\Users\rabby\AppData\Local\Temp\xmlXPathInitt0q8ob77.c(1): fatal error C1083: Cannot open include file: 'libxml/xpath.h': No such file or directory
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\BuildTools\\VC\\Tools\\MSVC\\14.16.27023\\bin\\HostX86\\x86\\cl.exe' failed with exit status 2
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Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?
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命令“ E：\ TestProject \ venv \ Scripts \ python.exe -u -c”导入setuptools，标记化； 文件 ='C：\ Users \ rabby \ AppData \ Local \ Temp \ pip-install- muzepxbu \ lxml \ setup.py'; f = getattr（tokenize，'open'，open）（file）; code = f.read（）。replace（'\ r \ n'，'\ n' ）; f.close（）; exec（compile（code，file，'exec'）））“安装--record C：\ Users \ rabby \ AppData \ Local \ Temp \ pip-record-0023ymbj \ install -record.txt-单一版本-外部管理-编译--install-headers E：\ TestProject \ venv \ include \ site \ python3.8 \ lxml失败，错误代码为1：C：\ Users \ rabby \ AppData \ Local \ Temp \ pip-install-muzepxbu \ lxml \