As a Python user, I'll give my personal reason for using Python over Ruby. Upfront: I think Ruby is absolutely fantastic. It's a very elegant language. In a lot

As a Python user, I'll give my personal reason for using Python over Ruby. Upfront: I think Ruby is absolutely fantastic. It's a very elegant language. In a lot of ways I think it's cleaner than python. I'd love to use it. Except... Every interpreter I've tried is just too slow. I recently ported over a networking library I wrote in python to ruby, and the requests per second (CPU limited in this case, since it was talking over a loopback socket -- this was just a test of how fast data could be serialized/deserialized) dropped from 7000 requests/sec in python to 120 in ruby. And that was just with standard CPython. Under PyPy, I was able to process about 20,000 requests/sec after letting the JIT warm up. I realize it's sort of silly to choose a dynamically typed interpreted language on the grounds of performance when you're already giving up so much performance regardless, but in my mind python hits the sweet spot of "just fast enough for most things I need to do", and with all other things being roughly equal (which, in my opinion, they roughly are), being an order of a magnitude factor faster wins out.