Python comparing version strings problem - alternatives to StrictVersion?

veryangryman

Below i am using StrictVersion in Python.

logging.info("Comparing " + deployment_version.strip() + " with " + latest_green_iso.strip())
if deployment_version.strip() <= latest_green_iso.strip():
logging.info("Yep less")

If the first comparison string is less than the second, the next line prints "Yep less".
As you can see, if the first 2 parts of Strings are alike, the third seems to be (wrongly) assumed to be greater, so python will not print the message.

[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,294] Comparing 1.31.9 with 1.31.11
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.31.9 with 1.31.11
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.31.8 with 1.31.11
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.31.6 with 1.31.11
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.31.4 with 1.31.11
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.30.90 with 1.31.11
[INFO][get_suitable_deployment.py:151][2016-10-26 21:07:39,295] Yep less
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,295] Comparing 1.30.88 with 1.31.11
[INFO][get_suitable_deployment.py:151][2016-10-26 21:07:39,295] Yep less
[INFO][get_suitable_deployment.py:149][2016-10-26 21:07:39,296] Comparing 1.30.79 with 1.31.11
[INFO][get_suitable_deployment.py:151][2016-10-26 21:07:39,296] Yep less


What is up with that? Any alternative method to compare version Strings?

duffman85

StrictVersion doesn't have a strip method, so I think you're still using string comparison.
So shouldn't it be:

StrictVersion(deployment_version.strip()) <= StrictVersion(latest_green_iso.strip())

http://stackoverflow.com/questions/11887762/compare-version-strings