[Distutils] workflow recommendations to update requirements.txt

[Nick Coghlan]

On 16 December 2015 at 16:40, Glyph Lefkowitz <glyph at twistedmatrix.com> wrote:
> On Dec 15, 2015, at 8:56 PM, Chris Jerdonek <chris.jerdonek at gmail.com>
> wrote:
> Thanks for any help or suggestions.
>
>
> This is what I'm doing right now (occasionally manually curating the output
> of `pip freeze´) but I have heard good things about
> https://github.com/nvie/pip-tools/ and I intend to investigate it.  As I
> understand it, pip-compile is the tool you want.

I just ran across pip-tools recently myself, and while I haven't
actually tried it out yet, I think the design makes a lot of sense for
the VCS-based deployment case:

* you write a requirements.in file with your direct dependencies
(including any pinning required for API compatibility)
* pip-compile turns that into a requirements.txt that pins all your
dependencies to their latest versions
* pip-sync makes a virtualenv *exactly* match a requirements.txt file
(installing, uninstalling, upgrading and downgrading as needed)

That makes "upgrade dependencies" (by rerunning pip-compile) a clearly
distinct operation from "deploy current dependencies" (by using
pip-sync in an existing environment, or by installing into a fresh
environment based on the generated requirements.txt).

I'm not sure it makes as much sense in the case where the thing you're
working on is itself a distributable Python package with its own
setup.py - it seems like you'd end up duplicating information between
setup.py and requirements.in.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia