Translate into French it ain't over till the fat lady sings?

"Tant qu'il y a de la vie, il y a de l'espoir." = As long as there is life, there is hope. "Il ne faut pas vendre la peau de l'ours avant de l'avoir tué." = Literally "you must not sell the skin of the bear before you've killed it", but more like "don't count your chickens before they've hatched".