How to clean weight groups by script?

Question

After transferring weights from one object to another vertices might get multiple groups with very low weights. In weight painting view there is a tool 'Clean' that allows to remove all the groups with low weights.

To automate the process I am trying a script like

for obj in bpy.context.visible_objects:
    if obj.name[-2:] == '-l':
        obj.vertex_group_clean(group_select_mode='ALL', limit=0.005, keep_single=True)

In this snippet I go through visible objects, and if their name ends with "-l" I want to run vertex_group_clean method, but the script fails with AttributeError: 'Object' object has no attribute 'vertex_group_clean'

What do I do wrong?

Answer 1

I did come up with a solution, but probably not the most elegant one. The vertex_group_clean method is an accessor to a menu, it is not a method to an object. So in the solution I select and activate an object, then switch to weight view, select all the vertices, do cleaning, and switch back to object view.

def active(obj):
    bpy.ops.object.select_all(action='DESELECT')
    obj.select=True
    bpy.context.scene.objects.active = obj
    bpy.ops.object.mode_set(mode = 'OBJECT')

for obj in bpy.context.visible_objects:
    if obj.name[-2:] == '-l':
        active(obj)
        bpy.ops.paint.weight_paint_toggle()
        bpy.ops.paint.vert_select_all(action="SELECT")
        bpy.ops.object.vertex_group_clean(group_select_mode='ALL', limit=0.005, keep_single=True)
        bpy.ops.paint.vert_select_all(action="DESELECT")
        bpy.ops.paint.weight_paint_toggle()

It does the job, but I hope there is a better way to write this :)