I looked at python-apt and python-debian, and they don't seem to have functionality to compare package versions. Do I have to write my own, or is there something I can use?
Ideally, it would look something like:
>>> v1 = apt.version("1:1.3.10-0.3")
>>> v2 = apt.version("1.3.4-1")
>>> v1 > v2
True
Perhaps because the title doesn't mention Python (though the tags do), Google brought me here when asking the same question but hoping for a bash answer. That seems to be:
$ dpkg --compare-versions 11a lt 100a && echo true
true
$ dpkg --compare-versions 11a gt 100a && echo true
$
To install a version of rubygems that's at least as new as the version from lenny-backports in a way that gives no errors on lenny and squeeze installations:
sudo apt-get install rubygems &&
VERSION=`dpkg-query --show --showformat '${Version}' rubygems` &&
dpkg --compare-versions $VERSION lt 1.3.4-1~bpo50+1 &&
sudo apt-get install -t lenny-backports rubygems
Perhaps I should have asked how to do that in a separate question, in the hope of getting a less clunky answer.
return subprocess.call(['dpkg', '--compare-versions', '11a', 'gt', '100a']) == 0
dpkg available.You could use apt_pkg.version_compare:
import apt_pkg
apt_pkg.init_system()
a = '1:1.3.10-0.3'
b = '1.3.4-1'
vc = apt_pkg.version_compare(a,b)
if vc > 0:
print('version a > version b')
elif vc == 0:
print('version a == version b')
elif vc < 0:
print('version a < version b')
yields
version a > version b
Thanks to Tshepang for noting in the comments that
for newer versions: apt.VersionCompare is now apt_pkg.version_compare.
apt.version_compare doesn't work. Use apt_pkg.version_compare instead.
ValueError: _system not initialized if I use apt_pkg.version_compare().python-debian can do this too. It's used in an almost identical way to python-apt:
from debian import debian_support
a = '1:1.3.10-0.3'
b = '1.3.4-1'
vc = debian_support.version_compare(a,b)
if vc > 0:
print('version a > version b')
elif vc == 0:
print('version a == version b')
elif vc < 0:
print('version a < version b')
ouput:
version a > version b
As you already mentioned python-apt and python-debian, but it is 2022 by now and Python 2.7 is end-of-life, here's the Python 3 code for a Debian based system, where you have installed python3-debian:
from debian.debian_support import Version
v1 = Version("1:1.3.10-0.3")
v2 = Version("1.3.4-1")
print(v1 > v2)
python3-debian will automatically used the more efficient version from python3-apt if it is installed. But you also can use it explicitly by importing Version from apt:
from apt import Version
