解析 JSON - TypeError：字符串索引必须是整数

Question

I need to retrieve GoDaddy certificates name and expiration dates. I`m trying code like this:

def get_cert():
    customerId = "UUID"
    cert_url = "https://api.godaddy.com//v2/customers/%s/certificates" %(customerId)

    cert_response = requests.get(cert_url, headers=headers)
    cert_dict = json.loads(cert_response.text)
    for cert in cert_dict:
        cert_name = (cert['commonName'])
        print(cert_name)

and getting error like:

    cert_name = (cert['commonName'])
TypeError: string indices must be integers

Output from the API call without parsing:

        {
            "certificateId": "ID", 
            "commonName": "*.domain.co.uk", 
            "completedAt": "2021-01-12T14:26:36Z", 
            "createdAt": "2020-04-02T14:25:06Z", 
            "period": 1, 
            "serialNumber": "NUMBER", 
            "status": "CURRENT", 
            "type": "DV_WILDCARD_SSL", 
            "validEndAt": "2022-05-04T14:26:32Z", 
            "validStartAt": "2021-04-02T14:26:32Z"
        }

I have the same code for GoDaddy domains API and it works properly (logic is the same, difference only in API URL and keys) so I can`t understand why its forbidden to cut json output by "commonName" and "validEndAt" in this case.

Answer 1

Be sure that what you are receiving is the data type you are assuming it is. The code you have is suitable if the decoding yields a list instance containing dict objects. The error message you are receiving seems like you are getting a single dict .

When you iterate through a dict , you will receive all its keys. If you know exactly what key you want, you don't need to iterate over it.

def get_cert():
    customerId = "UUID"
    cert_url = "https://api.godaddy.com//v2/customers/%s/certificates" %(customerId)

    cert_response = requests.get(cert_url, headers=headers)
    cert_dict = json.loads(cert_response.text)
    print(cert_dict['commonName'])

This will throw an error if the key does not exist. Another way to try to retrieve it without any exceptions would be:

common_name = cert_dict.get('commonName')

If the key is not there, common_name would be None