Set all shader attributes to a new prefixed and indexed string

set_all_aovIds.py

import pymel.core as pm

def set_all_aovIds(value, targets=None, object_type='alSurface', padding=2, attr_basename='aovId', number_of_indexes=8, use_selection=True):
    if not targets:
        targets = pm.ls(type=object_type, sl=use_selection)
        
    for target in targets:
        for index in range(1, number_of_indexes+1):
            try:
                new_value = '%s_%{PAD}d'.format(PAD='0' + str(padding)) % (value, index)
                target.attr(attr_basename+str(index)).set(new_value, type="string")
            except pm.MayaAttributeError:
                print('Attribute %s did not exist.' % attr_basename+str(index))
                
# changing padding
# set_attributes_in_order("test", padding=4)

# changing shader we're looking for
# set_attributes_in_order("test", object_type='aiSurface')

# changing to set less aovIds
# set_attributes_in_order("test", number_of_indexes=4)