Not sure if there are interpreters for either of those languages for the DS- a handful of interpreted languages exist with the most useful being lua which has a few nice implementations and a lot of example code (after that you are more or less on basic or Java and neither of those are that well implemented or all that effective, I can not speak for python other than next to nobody uses it
https://www.develer.com/trac/dspython/ or if they do they do not share the work (not impossible but very unlikely)).
To this end it is C or C++ the main library/toolchain is devkitpro
http://devkitpro.org/
On top of this/alongside this there is also palib. There is little love lost between some in the devkitpro and pablib camps but when it comes down to it palib is a bit slower and bit clunky but it does make life easier for a lot of programmers and is still quite capable of turning out great little programs
http://www.palib.info/
If you are coming from some of the really high level languages (it sounds like you are doing this at a university- at the risk of incurring the wrath of the lisp fans that is about the only place that really still uses it) then palib is probably your better bet.
Various people have made various libraries as well but I suggest not venturing into that until you need to.
That is all somewhat besides the point though as you asked for programming guides
http://www.patater.com/manual is the main one we tend to point people at.
http://www.palib.info/wiki/doku.php is a bit palib specific but it gets you started at least.
http://www.coranac.com/tonc/text/toc.htm is for the GBA and quite an old toolchain in places but it covers loads and is really good for some of the low level stuff.
Speaking of low level stuff the main hardware specs for the DS
http://nocash.emubase.de/gbatek.htm You might never have to use that but it is worth having around.
http://dev-scene.com/NDS/Tutorials_Day_1 is also worth a look although it is getting a bit old.
There are many others but if those are not enough I would instead head back and learn some C or C++ a bit before diving in again.
To finish the usual- there are hundred if not thousands of pieces of DS homebrew and the vast majority of them are open source.