解决virtualenv -p python3 venv报错的问题
在阿里云服务器上，用virtualenv创建虚拟环境时，报了个错误
root@iZwz982qla1uxm1s5dnyo7Z:/usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info#virtualenv-ppython3venv Runningvirtualenvwithinterpreter/usr/bin/python2 Newpythonexecutablein/usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info/venv/bin/python2 Notoverwritingexistingpythonscript/usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info/venv/bin/python(youmustuse/usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info/venv/bin/python2) Pleasemakesureyouremoveanypreviouscustompathsfromyour/root/.pydistutils.cfgfile. 1[global] Installingsetuptools,pkg_resources,pip,wheel... Completeoutputfromcommand/usr/lib/python3/dis...nfo/venv/bin/python2-setuptoolspkg_resourcespipwheel: Collectingsetuptools Downloadinghttp://mirrors.aliyun.com/pypi/packages/ff/f4/385715ccc461885f3cedf57a41ae3c12b5fec3f35cce4c8706b1a112a133/setuptools-40.0.0-py2.py3-none-any.whl(567kB) Collectingpkg_resources Exception: Traceback(mostrecentcalllast): File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/basecommand.py",line209,inmain status=self.run(options,args) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/commands/install.py",line328,inrun wb.build(autobuilding=True) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/wheel.py",line748,inbuild self.requirement_set.prepare_files(self.finder) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/req/req_set.py",line360,inprepare_files ignore_dependencies=self.ignore_dependencies)) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/req/req_set.py",line512,in_prepare_file finder,self.upgrade,require_hashes) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/req/req_install.py",line273,inpopulate_link self.link=finder.find_requirement(self,upgrade) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/index.py",line442,infind_requirement all_candidates=self.find_all_candidates(req.name) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/index.py",line400,infind_all_candidates forpageinself._get_pages(url_locations,project_name): File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/index.py",line545,in_get_pages page=self._get_page(location) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/index.py",line648,in_get_page returnHTMLPage.get_page(link,session=self.session) File"/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl/pip/index.py",line760,inget_page resp.raise_for_status() File"/usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info/venv/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/models.py",line840,inraise_for_status raiseHTTPError(http_error_msg,response=self) HTTPError:404ClientError:NotFoundforurl:http://mirrors.aliyun.com/pypi/simple/pkg-resources/ ---------------------------------------- ...Installingsetuptools,pkg_resources,pip,wheel...done. Traceback(mostrecentcalllast): File"/usr/lib/python3/dist-packages/virtualenv.py",line2363,inmain() File"/usr/lib/python3/dist-packages/virtualenv.py",line719,inmain symlink=options.symlink) File"/usr/lib/python3/dist-packages/virtualenv.py",line988,increate_environment download=download, File"/usr/lib/python3/dist-packages/virtualenv.py",line918,ininstall_wheel call_subprocess(cmd,show_stdout=False,extra_env=env,stdin=SCRIPT) File"/usr/lib/python3/dist-packages/virtualenv.py",line812,incall_subprocess %(cmd_desc,proc.returncode)) OSError:Command/usr/lib/python3/dis...nfo/venv/bin/python2-setuptoolspkg_resourcespipwheelfailedwitherrorcode2
看到HTTPError:404ClientError:NotFoundforurl:http://mirrors.aliyun.com/pypi/simple/pkg-resources/以为是阿里云的安全组配置没配好，折腾了半天，原来是访问PyPI镜像源出了问题，将pip的默认的源地址改为国内源即可。
具体操作如下：
vim~/.pip/pip.conf打开pip配置文件:
写入
[global] index-url=http://e.pypi.python.org/simple
以下这几个国内源都可以
e.pypi.python.org
pypi.douban.com
pypi.hustunique.com
补充：使用virtualenv创建Python3.7虚拟环境时报错ModuleNotFoundError:Nomodulenamed'_ctypes'的解决方法
使用virtualenv创建Python3.7.6版本虚拟环境时，遇到了标题中的报错，记录一下解决过程。
出现这种情况一般是因为缺少依赖包libffi-devel
在安装3.7以上版本时，需要一个新的libffi-devel包做依赖
使用yum安装依赖
yuminstalllibffi-devel-y
删除之前安装的报错的虚拟环境目录
rm-fvenv
重新编译安装系统Python3.7.6（需要先找到安装时的Python源码包，cd到目录中）
./configure--prefix=/usr/local/python3 make&&makeinstall
删除之前建立的软连接
rm-rf/usr/bin/python3 rm-rf/usr/bin/pip3
重新建立软连接
ln-s/usr/local/python3/bin/python3.7/usr/bin/python3 ln-s/usr/local/python3/bin/pip3.7/usr/bin/pip3
到此Python3重新安装完成，可以用python3、pip3命令测试一下是否安装成功。
进入虚拟目录将要存放的目录，使用新安装的Python3创建虚拟环境。此处需要使用-p参数指定Python版本路径，否则默认创建Python2的环境。
virtualenv-p/usr/bin/python3venv
测试进入创建好的虚拟环境中
sourcevenv/bin/activate
退出环境
deactivate
以上为个人经验，希望能给大家一个参考，也希望大家多多支持毛票票。如有错误或未考虑完全的地方，望不吝赐教。