Bay of Angels (1964)

Despite Jean's disinterest in gambling, when his friend wins enough money on roulette to buy a car, Jean decides to tag along with him to the casino. He's quickly addicted and decides to go to enjoy his new hobby during a week off of work. 

Soon he's hooked up with Jackie, a woman who's sacrificed her marriage and young son to roulette. Jean and Jackie win a ton and live the high life only to lose it all and head back to the cheaper parts of town. And that's about it.

C