Could you give examples of useful closures (actually multi-line lambda) ? I am relatively proeficient in python, and am learning javascript, and I really don't

Could you give examples of useful closures (actually multi-line lambda) ? I am relatively proeficient in python, and am learning javascript, and I really don't like how non trivial anonymous functions are pervasive in the later. I understand it may just be habit, though.... OTOH, one nice aspect in say ruby is the combo "real" anonymous functions + the syntax f a equivalent of f(a), which is what makes DSL possible in ruby (and impractical in python in general). I think it comes at a price in readability, though.