They're a weird combo of compile-time parsing and run-time expressions, with custom opcode. Early on they didn't have expressions but worked like .format(). T

They're a weird combo of compile-time parsing and run-time expressions, with custom opcode. Early on they didn't have expressions but worked like .format(). Then they added expressions and the PEP title needed differentiation from it. Not entirely accurate title is now set in stone. I would have called them "interpolated strings" or even e-string but the f-string moniker had already caught on and there was no stopping it.