French is normal thread both sides (no left hand on drive side, like you find on modern british standard). Swiss is left hand thread on drive side, 35.0 x 1.0 marked.

British standard is 1.37 x 24 thread (usually marked).

Clipped from Sheldon's site:

Many Swiss bikes, and French bikes sold in the late 1970s/early '80s (especially Motobécanes and later Peugeots) used the now-obsolete Swiss bottom-bracket threading:
35 mm x 1mm (1.378" x 25.4 TPI), left-hand-threaded fixed cup (right side), right-hand-threaded adjustable cup (left side.)
The diameter and thread pitch are the same as French, but the Swiss fixed (right side) cup has a left-hand thread.