python3 won't run from mac shell script

Question

I am trying to use Automator on macOS 10.12 to launch a Python 3 script. The script works just fine when I run it from the terminal with the command: python3 my_script.py.

Automator has a "Run Shell Script" function that uses the /bin/bash shell. The shell will run scripts with the command: python my_script.py, but this only seems to work for scripts written in Python 2.7.

My script starts with #!/usr/bin/env python3, which I thought would direct the shell to the correct python interpreter, but that doesn't seem to be the case.

As a workaround, I can get the script to run if I insert the full path to the python interpreter: /Library/Frameworks/Python.framework/Versions/3.5/bin/python3, but I see this as suboptimal because the commands might not work if/when I update to Python 3.6.

Is there a better way to direct the /bin/bash shell to run Python3 scripts?

Answer 1

Since you have the shebang line, you can do ./my_script.py and it should run with Python 3.

Answer 2

You can install Python 3 via Homebrew with brew install python3 and use #!/usr/local/bin/python3 as your shebang.

Not a perfect solution but still better than using the full path of the interpreter.