类型错误：使用 Python 解析 Json 时，字符串索引必须是整数错误

Question

Before you judge and think to yourself 'I've seen this question a thousand times' please read on and give me a chance, I've scoured the internet for answers but can't seem to find any help.

So I am trying to parse json from an API which I obtain using the following code:

url = 'https://api.companieshouse.gov.uk/company/' + companyno + '/charges'

r = requests.get(url, auth=('API KEY', ''))

data = r.json()

I can get specific values from the json pretty easily, for example using this code:

for each in data['items']:
    print(each['created_on'])

which returns:

2016-11-08
2016-11-08
2016-11-08
2015-03-27
2015-03-27
2015-03-27
2015-03-27
2015-03-27
2007-10-10
2007-09-28
2007-09-19

And this is exactly what I want, it works for other keys to.

However there is one bit of the json which I just can't seem to access, I have slightly edited the json as to avoid releasing sensitive data (which is available to the public anyway but just to be cautious) but it is largely unchanged:

{  
   'items':[  
      {  
         'created_on':'2016-11-08',
         'etag':'DELETED',
         'classification':{  
            'type':'charge-description',
            'description':'A registered charge'
         },
         'particulars':{  
            'contains_negative_pledge':True,
            'description':'DELETED',
            'type':'brief-description'
         },
         'transactions':[  
            {  
               'links':{  
                  'filing':'DELETED'
               },
               'filing_type':'create-charge-with-deed',
               'delivered_on':'2016-11-21'
            }
         ],
         'links':{  
            'self':'DELETED'
         },
         'charge_code':'DELETED',
         'delivered_on':'2016-11-21',
         'status':'outstanding',
         'persons_entitled':[  
            {  
               'name':'DELETED'
            },
            {  
               'name':'DELETED'
            }
         ],
         'charge_number':59
      },
      {  
         'transactions':[  
            {  
               'delivered_on':'2016-11-10',
               'links':{  
                  'filing':'DELETED'
               },
               'filing_type':'create-charge-with-deed'
            }
         ],
         'particulars':{  
            'contains_negative_pledge':True,
            'contains_fixed_charge':True,
            'floating_charge_covers_all':True,
            'contains_floating_charge':True
         },
         'persons_entitled':[  
            {  
               'name':'DELETED'
            }
         ],
         'charge_number':58,
         'status':'outstanding',
         'charge_code':'DELETED',
         'links':{  
            'self':'DELETED'
         },

It is the [items, links, self] data

If I use the following code to try and access it:

for each in data['items']['links']:
    print(each['self'])  

I get the following error:

  File "<stdin>", line 1, in <module>
TypeError: list indices must be integers or slices, not str

And if I try to access it using the following code:

for each in data['items'][0]['links']:
        print(each['self'])

I get this error:

  File "<stdin>", line 2, in <module>
TypeError: string indices must be integers

I just cant understand why its throwing this error at me, all the other responses on the internet point towards the fact that I am trying to parse a string and not an actual json object but whenever I run the command:

type(data)

it returns:

<class 'dict'>

So I know it is a dictionary and that it should be able to iterate through the keys.

I'm sure I'm making a very stupid mistake and if so I apologize but I just can't figure out what I'm doing wrong, can anyone help?

ps sorry for the long post.

EDIT:

Thanks so much for all your replies, things seems to make sense now. We were all learners at one point! :)

Answer 1

The 'links' key is pointing to a dictionary value, so iterating over it gives you the key(s) of the dictionary which in this case is 'self' . You should do:

for k, v in data['items'][0]['links'].items():
    if k == 'self':
        print(v)

Or you can simply access the value at key 'self' without iterating:

print(data['items'][0]['links']['self'])

Answer 2

In case there's more than one item in that response, do

for item in data['items']:
    print(item['links']['self'])

otherwise print(data['items'][0]['links']['self']) is sufficient.

Alternatively, you could use JSONPath (which is similar to XPath):

import jsonpath_rw as jp

for match in jp.parse('items[*].links.self').find(data):
    print(match.value)

Answer 3

data['items'][0]['links']: is a dict: { 'self':'DELETED' }

Iterating over a dict yields its keys: in this case, just one, 'self'. `'self'['self'] accounts for your error

What you want is possibly just data['items'][0]['links']['self'] , or iterate over one of the dict methods .keys() , .values() or .items()

for key,value in data['items'][0]['links'].items()
   print(key,":",value)