I've never heard of that. What I have heard, though, is that string operations are more expensive in pypy than cpython. Regardless, performance gains and regr

I've never heard of that. What I have heard, though, is that string operations are more expensive in pypy than cpython. Regardless, performance gains and regressions are unlikely to generalize; what's true for someone else's project may not be true for yours. If you're concerned about performance, I recommend benchmarking your own codebase.