I guess then that if you were to use only a single language then python would not be a good choice although it may be good to mix it up as you say. For small parts of your research sometimes it's better to focus on one language though, especially if you don't know the others. I like C/C++ for...
Seriously, since you are a physicist I assume you wish to do some heavy calculations. If that is the case then forget about python and the such, you want a compiled language as they are much faster. Even though it is archaic, FORTRAN is still the fastest language to program in for physics...