pip安装pymssql模块时报错“PEP 517”怎样处理

pip安装pymssql模块时报错“PEP 517”怎样处理？

报错信息
如下图：

[root@centos tmp]# pip3 install pymssqlCollecting pymssql  Using cached https://files.pythonhosted.org/packages/4a/20/bcd4db9e7990b50e85280f0c9488c0a53f7e6bf9048203448d8e0f29a536/pymssql-3.0.3.tar.gz  Installing build dependencies ... done  Getting requirements to build wheel ... done  Installing backend dependencies ... done    Preparing wheel metadata ... doneBuilding wheels for collected packages: pymssql  Building wheel for pymssql (PEP 517) ... error  ERROR: Command errored out with exit status 1:   command: /usr/local/python3/bin/python3.7 /usr/local/python3/lib/python3.7/site-packages/pip/_vendor/pep517/_in_process.py build_wheel /tmp/tmplktlmv2p       cwd: /tmp/pip-install-6x1763de/pymssql  Complete output (42 lines):  running bdist_wheel  running build  installing to build/bdist.linux-x86_64/wheel  running install  /tmp/pip-build-env-b2tk6mrs/overlay/lib/python3.7/site-packages/setuptools/dist.py:46: DistDeprecationWarning: Do not call this function    warnings.warn("Do not call this function", DistDeprecationWarning)    ...(此处略去1000+字)File "/usr/local/python3/lib/python3.7/distutils/cmd.py", line 313, in run_command      self.distribution.run_command(command)    File "/usr/local/python3/lib/python3.7/distutils/dist.py", line 985, in run_command      cmd_obj.run()    File "setup.py", line 449, in run      raise DeprecationWarning(msg)  DeprecationWarning: The pymssql project has been discontinued.  To install the last working released version, use a  version specifier like "pymssql<3.0".  For details and alternatives see:   pymssql/pymssql/issues/668

  ERROR: Failed building wheel for pymssql  Running setup.py clean for pymssqlFailed to build pymssqlERROR: Could not build wheels for pymssql which use PEP 517 and cannot be installed directly

遇到问题不要怕，也不要慌，沉着冷静，总有处理方法。
仔细看报错信息，忽然有一条实际上已经告诉了答案。就是版本不匹配，
，那如何才能版本匹配呢？
需要低于3.0版本的pymssql才能安装。

处理命令
命令如下：

pip install "pymssql<3.0"pip list

总结
当报错信息是版本不匹配时，按照提醒信息，输入正确的版本限制语法，安装就成功了。