Listening to Douce France one only thinks about Charles Trénet but the music is by Léo Chauliac who was the pianist for Trénet from 1938 to 1943. He also did the music for Que reste-t-il de nos amours. Later for Jean-Claude Pacal, Nous les amoureux.
Here the link to the chronicle by Bertrand Dicale about Douce France (in French). He does not mention Léo...