[Biopython] Entrez.esearch sort by publication date

[Renato Alves]

Hi everyone,

I've been using Entrez.esearch for a while without problems but today I
wanted to have the results sorted by publication date.

According to the docs at:
http://www.ncbi.nlm.nih.gov/corehtml/query/static/esearch_help.html#Sort
I should use 'pub+date', however this doesn't work. If I use 'author'
and 'journal' I have no problems but if I use 'last+author' or
'pub+date' I get an empty reply:

>>>Entrez.esearch(db='pubmed', term=search, retmax=5,
sort='pub+date').read()
<?xml version="1.0" ?>\n<!DOCTYPE eSearchResult PUBLIC "-//NLM//DTD
eSearchResult, 11 May 2002//EN"
"http://www.ncbi.nlm.nih.gov/entrez/query/DTD/eSearch_020511.dtd">\n<eSearchResult><Count/><RetMax/><RetStart/><TranslationSet/><QueryTranslation/></eSearchResult>\n'

Any suggestions on how to make this work?

Thanks,
Renato