import bpy

for arm in bpy.data.objects:
    if arm.type == 'ARMATURE': 
        
        for b in arm.pose.bones:
            name = "courbe"
            mesh = bpy.data.meshes.new(name)

            vertices = []
            edges = []
            faces = []
        
            edges_position = 0
            
            for p in b.motion_path.points:
                vertices.append([p.co[0],p.co[1],p.co[2]])
                
            lenverts = len(vertices)    
            print(lenverts)
            
            for v in range(lenverts-1):
                edges.append([edges_position +v, edges_position + v +1])
            
            mesh.from_pydata(vertices, edges, faces)
            
            ob_new = bpy.data.objects.new(name, mesh)
            bpy.context.scene.objects.link(ob_new)