We don’t have access to these buttons from python. But you can create your own. Add Float Properties with these getter and setter (edge_crease_and_bevel_weight.json):
Edge Bevel Weight Getter:
import bmesh; obj = C.edit_object; me = obj and obj.type == 'MESH' and obj.data; bm = me and bmesh.from_edit_mesh(me); l = me and bm.edges.layers.bevel_weight.verify(); e = me and find_by(bm.edges, "select", True); return e[l] if e else 0
Edge Bevel Weight Setter:
import bmesh; obj = C.edit_object; me = obj and obj.type == 'MESH' and obj.data; bm = me and bmesh.from_edit_mesh(me); l = me and bm.edges.layers.bevel_weight.verify(); me and [e.__setitem__(l, value) for e in bm.edges if e.select]; me and bmesh.update_edit_mesh(me)
Edge Crease Getter:
import bmesh; obj = C.edit_object; me = obj and obj.type == 'MESH' and obj.data; bm = me and bmesh.from_edit_mesh(me); l = me and bm.edges.layers.crease.verify(); e = me and find_by(bm.edges, "select", True); return e[l] if e else 0
Edge Crease Setter:
import bmesh; obj = C.edit_object; me = obj and obj.type == 'MESH' and obj.data; bm = me and bmesh.from_edit_mesh(me); l = me and bm.edges.layers.crease.verify(); me and [e.__setitem__(l, value) for e in bm.edges if e.select]; me and bmesh.update_edit_mesh(me)
You can use these properties in Menu
tab.