如何从嵌套字典中提取元素

Question

1.I need to get the value for business' name and append it to a list.

2.I need to get the value policies and append to a list after checking parent.

3.if parent is Marketing name has to added to level1.

4.if parent is Advertising name has to added to level2.

5.if some place Business is [] I need to pass None instead of Null List

6. Also need to check key exists or not for some keys there is a chance of missing policies, business

Sample dictionary is below

searchtest = [{'_index': 'newtest',
  '_type': '_doc',
  '_id': '100',
  '_score': 1.0,
  '_source': {'id': '100',
   'name': 'A',
   'Business': [{'id': '7', 'name': 'Enterprise'},
    {'id': '8', 'name': 'Customer'}],
   'policies': [{'id': '332',
     'name': 'Second division',
     'parent': 'Marketing'},
    {'id': '3323', 'name': 'First division', 'parent': 'Marketing'}]}},
 {'_index': 'newtest',
  '_type': '_doc',
  '_id': '101',
  '_score': 1.0,
  '_source': {'id': '101',
   'name': 'B',
   'Business': [{'id': '7'},
    {'id': '8', 'name': 'Customer'}],
   'policies': [{'id': '332',
     'name': 'Second division',
     'parent': 'Marketing'},
    {'id': '3323', 'name': 'First division', 'parent': 'Marketing'}]}}]

Expected out

[
  {
    "id": "100",
    "name": "A",
    "Business": ["Enterprise", "Customer"],
    "level1": ['Second division', 'First division'],
    "level2": [ ]
  },
  {
    "id": "101",
    "name": "B",
    "Business": ["Enterprise", "Customer"],
    "level1": ['Second division', 'First division'],
    "level2": [ ]
  }
]

COde is below

def do_the_thing(lst):
    resp = []

    parents_mapper = {
        'Marketing': 'level1',
        'Advertising': 'level2'
    }

    for el in lst:
        d = {
            'id': el['_source']['id'],
            'name': el['_source']['name'],
            'Business': [],
            'level1': [],
            'level2': []
        }
        for business in el.get("_source", {}).get("business", {}).get("name", ""):
            business_name = business.get('name')
            if business_name:
                d['Business'].append(business_name)

        for policy in el.get('policies', []):
            policy_parent = policy.get('parent')
            parent_found = parents_mapper.get(policy_parent)
            policy_name = policy.get('name')
            if parent_found and policy_name:
                d[parent_found].append(policy_name)

        resp.append(d)
    return resp


if __name__ == "__main__":
    import pprint
    pp = pprint.PrettyPrinter(4)
    pp.pprint(do_the_thing(searchtest))

My output

[   {'Business': [], 'id': '100', 'level1': [], 'level2': [], 'name': 'A'},
    {'Business': [], 'id': '101', 'level1': [], 'level2': [], 'name': 'B'}]

The problem in my output you can see: 'Business', 'level1' is [] is null list.

Adding one more dictionary for testing

searchtest = [{'_index': 'newtest',
  '_type': '_doc',
  '_id': '100',
  '_score': 1.0,
  '_source': {'id': '100',
   'name': 'A',
   'policies': [{'id': '332',
     'name': 'Second division',
     'parent': 'Marketing'},
    {'id': '3323', 'name': 'First division', 'parent': 'Marketing'}]}},
 {'_index': 'newtest',
  '_type': '_doc',
  '_id': '101',
  '_score': 1.0,
  '_source': {'id': '101',
   'name': 'B',
   'Business': [{'id': '9'}, {'id': '10', 'name': 'Customer'}],
   'policies': [{'id': '332',
     'name': 'Second division',
     'parent': 'Marketing'},
    {'id': '3323', 'name': 'First division', 'parent': 'Advertising'}]}}]

• In the above dictionary you can see that there is no Business in 100 key and for 101 there is no name inside the Business key. So there will be key error will be coming. Need to handle that

Answer 1

You are not collecting data from dict, You have to select particular key to get it's value.

replace this:

for el in lst:
        d = {
            'id': el['_source']['id'],
            'name': el['_source']['name'],
            'Business': [],
            'level1': [],
            'level2': []
        }

with this:

for el in data:
        d = {
            'id'       : el['_source']['id'],
            'name'     : el['_source']['name'],
            'Business' : [name['name'] for name in el['_source']['Business']],
            'level1'    : [name['name'] for name in el['_source']['policies']],
            'level2'   : []
        }

output:

[   {   'Business': ['Enterprise', 'Customer'],
        'id': '100',
        'level1': ['Second division', 'First division'],
        'level2': [],
        'name': 'A'},
    {   'Business': ['Enterprise', 'Customer'],
        'id': '101',
        'level1': ['Second division', 'First division'],
        'level2': [],
        'name': 'B'}]