[Python-ideas] python_modules as default directory for dependencies in distutils
jimjjewett at gmail.com
Tue Nov 20 21:35:44 CET 2012
On 11/20/12, Daniel Holth <dholth at gmail.com> wrote:
> On Tue, Nov 20, 2012 at 1:21 PM, Philipp Hagemeister
> <phihag at phihag.de>wrote:
>> Currently, there are the following methods for installing dependencies:
>> Therefore, I'd like to suggest a new alternative location (--here =
>> --root "./python_modules", intended to become default in Python 5),
>> modeled after node's packaging system (http://goo.gl/dMRTC).
If I'm understanding correctly, you just mean "install dependencies
in the same place as the application that asked for them", or maybe in
a magically named subdirectory. That does sound like a reasonable
policy -- similar to the windows or java solution of packing
everything into a single bundle.
>> Aside from the new flag in distutils, the site module should
>> automatically look into ./python_modules , as if it were a second
As opposed to just putting them a layer up, and looking into the
application package's own directory for relative imports?
> You wouldn't need stdlib support to do this. I believe setuptools'
> pkg_resources can look in a directory full of eggs, adding the required
> ones to PYTHONPATH based on requirements as specified in a wrapper script.
> Gem uses a directory full of versioned packages like
If I understand correctly, that just provides a way to include the
version number when choosing the system-wide package location (and
later, when importing). Also useful, but different from bundling the
dependencies inside each application that requires them.
Most notably, the bundle-inside solution will* find exactly the module
it shipped with, including custom patches. The versioned-packages
solution will have conflicts when more than one application provides
for the same dependency, but will better support independent
maintenance (or at least security patches) for the 4th-party modules.
* Err, unless the module was loaded before the application, or
modified locally, or something odd happened with import, or ...
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