how to add to different field values and store it in another field in elastic search python (elastic search field operation)

I have written this elastic search query:

es.search(index=['ind1'],doc_type=['doc'])

I am getting following result:

{'_shards': {'failed': 0, 'skipped': 0, 'successful': 5, 'total': 5},
'hits': {'hits': [{'_id': '1327',
'_index': 'ind1',
'_score': 1.0,
'_source': {'val1': 1,
 'val2': None,
 'value1': 1327,
 'value2': 1531,
 'new_values': {'nv1': 1,
  'nv2': 0},
{'_id': '1349',
'_index': 'ind1',
'_score': 1.0,
'_source': {'val1': 2,
 'val2': 3,
 'value1': 1328,
 'value2': 1539,
 'new_values': {'nv1': 1,
  'nv2': 3}},.......

I want all the add val1, value1 and nv1 and store it in another field Let's call total. I want the result will be like:

{'_shards': {'failed': 0, 'skipped': 0, 'successful': 5, 'total': 5},
'hits': {'hits': [{'_id': '1327',
'_index': 'ind1',
'_score': 1.0,
'_source': {'val1': 1,
 'val2': None,
 'value1': 1327,
 'value2': 1531,
 'new_values': {'nv1': 1,
  'nv2': 0},
 'total1': 1329},
{'_id': '1349',
'_index': 'ind1',
'_score': 1.0,
'_source': {'val1': 2,
 'val2': 3,
 'value1': 1328,
 'value2': 1539,
 'new_values': {'nv1': 1,
  'nv2': 3},
  'total': 1331},.......

What you can do is use a script field in order to compute that value on the fly:

 es.search(index=['ind1'],doc_type=['doc'], body={
    '_source': true,
    'script_fields': {
      'total': {
        'script': {
          'source': 'doc.val1 + doc.value1 + doc.new_values.nv1'
        }
      }
    }
 })

The best way, though, would be to pre-compute that at index time and store the value in a new total field.