[Solved] Trying to move Weights from one VGroup to another in the Same Mesh Object using Python

Coding Python Support
1

I’ve created this tread on Blender Stack Exchange but thought others here might want to know or contribute to the discussion.

https://blender.stackexchange.com/questions/137675

Current Code is

import bpy
vgname1 = 'Leg_L'
vgname2 = 'LegD3_L'
vgi1 = -1
vgi2 = -1
vvgi1 = -1
vvgi2 = -1
verts=[]
vWeight=[]

#Get current mode and name for active object
mode = bpy.context.active_object.mode
obname = bpy.context.active_object.name
print(mode, obname)

#Walk through Vertex Groups and determine if the New Group
#already exists, if not, create the new Group Also Get the 
#index numbers for the 2 Groups in question

for ob in bpy.data.objects:
    if ob.name == obname:
        for vgn in ob.vertex_groups:
            if vgn.name == vgname1:
                vgi1 = vgn.index

            if vgn.name == vgname2:
                vgi2 = vgn.index

            if vgi2 == -1:
                ob.vertex_groups.new(name=vgname2)
                for vgn2 in ob.vertex_groups:
                    if vgn2.name == vgname2:
                        vgi2 = vgn2.index
#Test the results
        print( ob.name, vgname1,vgi1, vgname2, vgi2)

#Put the object into Object Mode and get the 
#vertexes that are currently assigned to the group to be removed
#Put the vertex indexes to be moved into a list

        bpy.ops.object.mode_set(mode = 'OBJECT')
        for v in bpy.context.active_object.data.vertices:
            for vg in v.groups:
                if vg.group == vgi1:
                    print(vg.group, vg.weight)
                    verts.append(v.index)
#Ignore            vWeight = vg.weight

#Now add the vertexes to the other group 

                    vg2 = ob.vertex_groups
                    for vga in vg2:
                        if vga.index == vgi2:
                            print(vga.index,vga.name)
                            vga.add(verts, 0, 'ADD')
2

Ok, this code is really clunky and inflated.
I know that you Python wizards out there can probably do this in 4 lines of code, but I’m just learning and don’t know the shortcuts in coding…(yet). I need to follow the logic without the statements like
for {i in blah: if foo = bar in whatever}. I just can’t wrap my head around those kind of statements yet.

But this does what I need it to do.
I you wish to share how it “should” be written, please do. But please add comments explaining why it is better and what your code does.

import bpy
vgname1 = 'Leg_R'
vgname2 = 'LegD_R'
vgi1 = -1
vgi2 = -1
vvgi1 = -1
vvgi2 = -1
verts=[]
vWeight=[]
x = 0
y = 0
z = 0
mode = bpy.context.active_object.mode
obname = bpy.context.active_object.name

for ob in bpy.data.objects:
    if ob.name == obname:
        
        for vgn in ob.vertex_groups:

            if vgn.name == vgname1:
                vgi1 = vgn.index
                x=x+1

            if vgn.name == vgname2:
                vgi2 = vgn.index
                y=y+1
                
        for vgn in ob.vertex_groups:

            if vgi2 == -1:
                z=z+1
                ob.vertex_groups.new(name=vgname2)

                for vgn2 in ob.vertex_groups:
                    if vgn2.name == vgname2:
                        vgi2 = vgn2.index

        bpy.ops.object.mode_set(mode = 'OBJECT')

        for v in bpy.context.active_object.data.vertices:

            for vg in v.groups:

                if vg.group == vgi1:
                    verts.append(v.index)
                    vg2 = ob.vertex_groups

                    for vga in vg2:

                        if vga.index == vgi2:
                            vga.add(verts, 0, 'ADD')

                    for v1 in bpy.context.active_object.data.vertices:

                        for vg1 in v1.groups:

                            if vg1.group == vgi1:
                                    vWeight = vg1.weight

                                    for v2 in bpy.context.active_object.data.vertices:

                                        if v2.index == v1.index:

                                            for vg2 in v2.groups:

                                                if vg2.group == vgi2:
                                                    vg2.weight = vWeight

            bpy.ops.object.vertex_group_set_active(group=vgname1)
            bpy.ops.object.vertex_group_remove()