在Heroku上部署Flask应用程序时出错“请求的运行时不可用于此堆栈”

Question

你知道吗 我正试图在Heroku上部署一个应用程序。我已经按照建议包含了runtime.txt文件和最新的python版本3.6.3，但是出现了以下错误。你知道吗

    -----> Python app detected
 !     The latest version of Python 3 is python-3.6.3 (you are using python 3.6.3, which is unsupported).
 !     We recommend upgrading by specifying the latest version (python-3.6.3).
       Learn More: https://devcenter.heroku.com/articles/python-runtimes


-----> Installing python 3.6.3
 !     Requested runtime (python 3.6.3) is not available for this stack (heroku-16).
 !     Aborting.  More info: https://devcenter.heroku.com/articles/python-support
 !     Push rejected, failed to compile Python app.
 !     Push failed