I also confirm that the dependency is indeed explicit on python3.4 and not only on python3, as simply checked.
> I don't understand what's the problem (python3-chardet requires python3 > >= 3.1.2-8~, python3 is currently python3.3, BTW). > The problem is that python3-chardet DOES indeed depend on python3.4 . Have a look to: https://packages.debian.org/sid/python3-chardet or type the following command: aptitude show python3-chardet/unstable