[Python-Dev] PEP 453 (pip bootstrapping) ready for pronouncement? (original) (raw)

Zachary Ware zachary.ware+pydev at gmail.com
Fri Sep 27 23:16:50 CEST 2013

On Fri, Sep 27, 2013 at 3:29 PM, Donald Stufft <donald at stufft.io> wrote:

> _If it lives in the source tree how are you going to provent it from existing when someone installs on Linux? OSX? One of the BSDs?_

If someone is building their own Python from source--regardless of platform--they're obviously going to have _ensurepip available one way or another, and such users will need to have it available to match the capabilities of the installer (or create their own). But if you're building your own Python, you should already know enough about what's going on to know when and whether _ensurepip should be used and how. On the other hand, when you use an installer (be it Windows, OSX, or otherwise), you really only need _ensurepip one time, ever: at install time. Even then, you don't actually need to know anything about _ensurepip at all, just whether to check the box or not. If you decide you need it later, you can always re-install.

It seems to me your [Terry's] proposal is to add the ensurepip module… except when they install it via Windows installer.

The way I read Terry's proposal, it is to never add the _ensurepip module, but to use (or make available, whichever makes sense in a given case) the _ensurepip script when it is requested at install-time: specifically, put _ensurepip.py in Tools/scripts, PC/, Mac/, or really anywhere but Lib/ so that builders can find it, but Python can't. In other words, don't make "import _ensurepip" possible out of the box, and a lot of the "don't add new features in maintenance releases" blockade disappears, because you aren't actually adding any new capability to Python itself or its standard library.

Of course, this proposal only applies to 2.7/3.3. Since _ensurepip will be used for venv as well as initial install in 3.4, it should be a full-blown stdlib module in that version, probably even without the leading underscore.

-- Zach

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