Python requests PUT request with json parameter fails and data parameter succeeds-CodePudding

Problem

I've looked at some of the documentation about the json and data parameters and the differences between them. I think I understand the difference, best explained here, in my opinion.

However, I have a specific request that fails on PUT using json, but fails using data, and I'm not sure why. Can someone clarify why this is the case? Could it be that there is a list in the payload?

Context

I have requests==2.28.0 installed. Below is the code that submits the PUT requests to an API for PagerDuty, the incident management software, one using data (successful) and one using json (failing). Otherwise they are identical.

The weird thing is that their examples use the json parameter.

payload = f'{{"source_incidents": [{{"id": "{child_incident_id}", "type": "incident_reference"}}]}}'

headers = {
    'Content-Type': "application/json",
    'Accept': "application/vnd.pagerduty json;version=2",
    'From': email,
    'Authorization': f"Token token={read_write_api_token}"
    }

response = requests.put(f'https://api.pagerduty.com/incidents/{parent_incident_id}/merge', data=payload, headers=headers)

print("response: ", response)

Result: response: <Response [200]>

payload = f'{{"source_incidents": [{{"id": "{child_incident_id}", "type": "incident_reference"}}]}}'

headers = {
    'Content-Type': "application/json",
    'Accept': "application/vnd.pagerduty json;version=2",
    'From': email,
    'Authorization': f"Token token={read_write_api_token}"
    }

response = requests.put(f'https://api.pagerduty.com/incidents/{parent_incident_id}/merge', json=payload, headers=headers)

print("response: ", response)

Result: response: <Response [400]>

CodePudding user response：

Your payload is a string while json parameter takes a dictionary. That's the whole point of the json argument (you don't have to encode it yourself):

If you need that header set and you don’t want to encode the dict yourself, you can also pass it directly using the json parameter (added in version 2.4.2) and it will be encoded automatically:

You should pass a dictionary if you want to use the json parameter:

payload = {
    "source_incidents": [
        {
            "id": child_incident_id,
            "type": "incident_reference"
        }
    ]
}

which is more readable anyway.

CodePudding user response：

Alternatively you could use json.loads to parse your string:

import json
payload = f'{{"source_incidents": [{{"id": "{child_incident_id}", "type": "incident_reference"}}]}}'
headers = {
    'Content-Type': "application/json",
    'Accept': "application/vnd.pagerduty json;version=2",
    'From': email,
    'Authorization': f"Token token={read_write_api_token}"
    }

response = requests.put(f'https://api.pagerduty.com/incidents/{parent_incident_id}/merge', data=json.loads(payload), headers=headers)

print("response: ", response)