How For Loops Compile

May 30, 2026 | 5 min read

Range Loops

for i in range(n) compiles to a simple counted loop in machine code.

List Iteration

for x in data uses fast iteration protocol with inline cache.

Enumerate

for i, x in enumerate(data) maintains index counter in a register.

Zip

for a, b in zip(list1, list2) iterates both lists in parallel.