Python -O won’t magically make every script faster, but in the right workloads it’s a free win—here’s how to test it safely.

Python’s new JIT compiler might be the biggest speed boost we’ve seen in a while, but it’s not without bumps. Get that news and more, in this week’s report.

JIT compiler stack up against PyPy? We ran side-by-side benchmarks to find out, and the answers may surprise you.