I've always mechanically written '#!/bin/bash' as my shebang for bash script, while I normally use '#!/usr/bin/env python' for python scripts. In retrospect, th

I've always mechanically written '#!/bin/bash' as my shebang for bash script, while I normally use '#!/usr/bin/env python' for python scripts. In retrospect, that sounds obviously incoherent. I would like to know if there is some common practice/standard around using '/usr/bin/env' in shebangs. Could you please elaborate more?