I have embraced this workflow completely. I used to be more concerned about which language, but now I find I much more useful to just start immediately in Python. I spend most of the time working out the kinks and edge cases, instead of memory management or other logistics. Maybe ~75% of the time, that's it, no need for further improvement.

Recently I chose to rewrite several thousands of lines of Python in Go, because we needed more speed and improved concurrency. Already having a working program and tests in Python was great. After figuring out a few Go-isms, it was a quick couple of days to port it all for big improvements.