[git] .gitignore is ignored by Git

My problem was that I wrote down files to ignore with quotes " " separation not with slash /.

This did not work and was ignored by git :

"db.sqlite3"
"tdd_venv/"

This worked just fine :

/db.sqlite3
/tdd_venv/

I also checked my file encoding in windows with Notepad++. Encoding was set to UTF-8.