Functions v1运行时不支持虚拟环境.

Virtual environments are not supported with the Functions v1 runtime. 

请参阅下面的链接，以了解如何安装Python的自定义版本以及如何使用第三方模块- 

Refer to the link below to learn how to install a custom version of Python and use third party modules with it - 

https://ourwayoflyf.com/running-python-code-on-azure- functions-app/

确保要安装的sqlalchemy版本与所安装的Python版本兼容.

Make sure the version of sqlalchemy you're installing is compatible with your version of Python installed. 

请注意，此功能目前是实验性"功能，我们不建议或不支持在生产环境中使用该功能.我们目前正在为v2运行时提供一流的Python支持，这将使这种情况变得更加简单- https://github.com/Azure/azure-functions-python-worker

Please note that this feature is currently 'experimental' and we don not recommend or support it for production scenarios. We're currently working on first-class Python support for the v2 runtime which will make this scenario a lot easier - https://github.com/Azure/azure-functions-python-worker