Script to Rename selected object same as the active object plus a suffix

Question

So what I want basically is as follows:- Basically I have two objects with different names. So lets say I select both of the Objects named "First" and "Second". So I make one of them named (First) as active selection. I want a script or addon which can rename the non-active object(named- Second) have the name of the first one but with a changeable suffix like say "_HP". So after applying the script I will have something like this. Don't mind the annotation/painted names those are so u can easily see which object is named which. Thank you!

Answer 1

You can use bpy.context.active_object and bpy.context.selected_objects. The first tells you the object that is active — the one you want to use as the source of the name. The second one tells you all of the selected objects, including the selected objects. The simplest script to do what you want in this case is

import bpy

name = bpy.context.active_object.name
suffix = "_toy"

for object in bpy.context.selected_objects:
    if not object.name == name:
        object.name = bpy.context.active_object.name + suffix
        break

You can enter this in the text editor, change the suffix string to whatever you like, and use the run key to run it.

It does have a bug, though. If you have selected multiple objects, it will rename the first one in the list, and it might not be the one you want.

It's also inconvenient, in that you have to edit it every time you change the prefix.

You could turn it into an add-on with an object mode panel that you could use to set the suffix, of course:

bl_info = {
    "name" : "renamer",
    "description" : "rename the selected object",
    "author" : "Marty",
    "version" : (0, 0, 1),
    "blender" : (2, 80, 0),
    "location" : "View3D",
    "warning" : "",
    "support" : "COMMUNITY",
    "doc_url" : "",
    "category" : "3D View"
}

import bpy

from bpy.types import Operator
from bpy.props import StringProperty
from bpy.types import Panel

class RENAMER_OT_Message(Operator):
    """ Renamer operator
        Renames the other selected object to the same name as
        the active object, with a suffix added.
    """
    bl_idname = "renamer.rename"
    bl_label = "rename"
    bl_description = "rename the selected object"
    bl_options = {"REGISTER"}
    
    @classmethod
    def poll(cls, context):
        return context.mode == "OBJECT"
    
    def execute(self, context):
        if not context.active_object:
           self.report({'ERROR'}, "No active object")
           return {'CANCELLED'}
        if len(context.selected_objects) != 2:
           self.report({'ERROR'}, "You must select two objects")
           return {'CANCELLED'}
        name = context.active_object.name
        for object in context.selected_objects:
            if not object.name == name:
                object.name = context.active_object.name + context.object.suffix
                break
        return {'FINISHED'}
    
class RENAMER_PT_Panel(Panel):
    """ Renamer panel
        A panel to display the renamer operator
    """
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_category = "renamer"
    bl_idname = "renamer.panel"
    bl_label = "rename selected"
    
    def draw(self, context):
        col = self.layout.column()
        col.prop(context.object, "suffix", text = "Suffix")
        col.operator("renamer.rename", text="rename")
        
classes = [
    RENAMER_OT_Message,
    RENAMER_PT_Panel,
]

def register():
    for c in classes:
        bpy.utils.register_class(c)
    bpy.types.Object.suffix= bpy.props.StringProperty(
        name="suffix",
        description="Suffix to add to name",
        default="_HP",
    )
    
def unregister():
    for c in classes:
        bpy.utils.unregister_class(c)
    del bpy.types.Object.suffix
    
if __name__ == '__main__':
    register()

Answer 2

Here is one trivial script that will rename per your (incomplete?) spec, where I've allowed for non-mesh other items (light, camera):

import bpy

suffix='HP'

if bpy.context.object is None:
    print('you need to select one object')
    
name_base=bpy.context.object.name

for obj in bpy.data.objects:
    if (obj is bpy.context.object) or (obj.type != 'MESH'):
        continue # skip selected
    obj.name=name_base+'_'+suffix
    break

The 'for all objects' loop breaks after renaming the first unselected object in the scene. Or one could have name objects, and use an incrementing index like

suffixIdx=0
.
.
.
    obj.name=name_base+'_'+ suffixIdx
    suffixIdx += 1
    # break   # remove the break statement

or gussie that up by formatting the suffixIdx so that the suffix is a three digit number preceeded by zeros like obj.name=name_base+'_'+suffix+'.{:03d}'.format(suffixIdx)