running python executable in linux

I've found a few other people asking this question, but the answers for their problem are not helping me. I trying to learn python and trying to make a file executable. The practice script runs when I type `python ./userPrompt.py`. But when I try to run it as an executable (just `./userPrompt.py`). I've successful change it `chmod +x` And here's what i have in the top line of the file: ``` #! /user/bin/env python ``` and here's the error I get ``` bash: ./userPrompt.py: /user/bin/env: bad interpreter: No such file or directory ``` But the thing is if I go to `/user/bin` I can find `env`. So it definitely exists. Why can't Ubuntu find it?? I appreciate any help people can give me on this.