Can't get tilde character with IDLE 3.2.2 on French Mac Lion

[Franck Ditter]

Hi !
All is in the subject. I'm starting to use Python with Idle 3.2.2
on MacOS-X Lion (French). I can't get "Option-N space" to provide 
the ~ char.
I tried to go into the Keys preferences but I can't find "Option-N space"
to modify its meaning. Its actual behavior is to merge lines of a 
paragraph.
Thanks for help !

   franck