This command will produce a leaderboard of TODO frequency for an entire repository
grep -r "TODO" . | awk '{print $1}' | cut -d ":" -f 1 | xargs -n 1 git blame --no-progress | grep TODO | cut -d "(" -f 2 | cut -d "-" -f 1 | rev | cut -c 5- | rev | awk '{$1=$1};1' | sort | uniq -c | sort -nr
Here are the first 10 lines from running the above in the cpython repo.
508 Serhiy Storchaka
281 David Scherer
139 Terry Jan Reedy