If it's CPython we're talking about, a function call can cause non-negligence performance impact in a hot loop. I wouldn't assume anything in Python is 'cheap'
Re:Flake8-Logging
by squeaky-clean on Monday September 11, 2023 @06:59PM
(#37474841)
Relative to python it's cheap. A set of Ferrari tires for $1000 is simultaneously expensive but also very cheap compared to the normal cost.
Basically, if you're worried about string formatting overhead, it's probably time to ditch Python.
I'd be more worried about cases where you're calling some function to produce a novel value that will then be included in the log string— and Python doesn't have lazy argument evaluation so you'll pay the cost of that function call regardless.