I'm doing some pretty heavy image recognition while stitching the output of a camera to image objects larger than the camera can see in one go from two different angles in real time. Python works fine for high performance numerical work, the only thing you have to keep an eye on is to use python as much as possible as the glue and the various libraries written in C or C++ to do the heavy lifting for you (and there are tons of such libraries).

The reason why python is the right tool for this job is because it has such libraries for just about everything, from serial communications to a bunch of hardware driving stepper motors, relays and reading inputs to imaging and number crunching and all the other bits that went into this. I'd have a much harder time achieving the same effect in any other language and likely it would have cost me a lot more time.

Python is not perfect (far from it) but it gets the job done.