ignore more files in Git?

Am I doing something wrong?

$ git status --ignored On branch edison-acpi Your branch is up to date with 'gh-andy-shev/edison-acpi'.

Ignored files: (use "git add -f <file>..." to include in what will be committed) tools/binman/__pycache__/ tools/binman/etype/__pycache__/ tools/concurrencytest/__pycache__/ tools/dtoc/__pycache__/ tools/patman/__pycache__/

nothing to commit, working tree clean