At 05:37 PM 6/21/2006 -0400, Jim Fulton wrote:
Suppose I have the directory:
/home/jim/tmp/dist: used 92 available 41345796 -rw-rw-r-- 1 jim jim 671 Jun 19 17:43 demoneeded-1.0-py2.4.egg -rw-rw-r-- 1 jim jim 672 Jun 19 17:46 demoneeded-1.1-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.2-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.3-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.4-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.5-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.6-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.7-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.8-py2.4.egg -rw-rw-r-- 1 jim jim 673 Jun 19 17:46 demoneeded-1.9-py2.4.egg
and then run easy install telling it to install something I already have:
[jim@ds9 ~]$ /usr/local/python/2.4/bin/easy_install -d tmp/dist -mxU demoneeded==1.1
The -U option means "always search PyPI".
I have some scripts that invoke easy_setup and I'd like to try to do some of this logic myself. Given a requirement, I'd like to get the specifiers and decide myself whether to invoke easy_install. I have 2 problems:
- I don't want to parse the requirement myself, but, rather, use Requirement.parse. If I use Requirement.parse, I can use the specs attribute to get the specifiers, however, this attribute isn't documented. Should I assume that it is private? Or is it safe to use.
Why do that when you can just ask the Requirement whether it matches a particular version? The __contains__ method of Requirement objects accepts a version string, distribution object, or parsed version number you can use. (For that matter, you can query an Environment or WorkingSet for the distributions whose versions you want to check.)