I could not find the correct solution to a similar problem of mine (with vim quitting unexpectedly) to quickly rollback to the previous version of python. 

Here is the oneliner I often use. In this case, it would be:

> Disclaimer: some programs from brew manager may require other versions of python due to their own dependencies.

```
brew update && brew install [email protected]_1 && brew unlink [email protected] && brew link [email protected]_1 --force && brew cleanup
```