Proper shebang for python3

[Chris Angelico]

On Sun, Jul 21, 2019 at 4:13 AM Michael Speer <knomenet at gmail.com> wrote:
>
> You may want to use `#!/usr/bin/env python3` instead.
>
> There is a concept in python called the virtual environment. This used to
> be done with a tool called virtualenv in python2, and is now done mainly
> through a venv module in python3.
>
> A virtual environment goes into a directory of your choosing and will have
> its own python3 executable, and pip3 executable, and when you add
> dependencies, they are also placed into the directory structure under your
> chosen directory.
>
> When you do a `. <directory>/bin/activate` the included source will places
> the virtual environment's bin/ folder at the beginning of your PATH
> environment variable, making it the default python3 when you type it
> without a full path.
>
> This allows you to run scripts that need different, or even conflicting,
> sets of dependencies without bothering with the underlying linux
> distribution's python installation's modules.
>
> If you use `#!/usr/bin/python3`, it will always use exactly the system
> version that is installed, and the system's installed modules.
>
> Your scripts will still default to the system installation if a virtual
> environment is not activated. So you lose nothing by doing it this way, but
> gain a little control from it.
>

ONLY if you actually want this script to behave differently inside a
venv. When you're setting a shebang on a script, you often do not want
that. You potentially LOSE a lot of control.

ChrisA