Request sending json

Question

I’m trying to make a request for the python. Follow what I’ve tried:

    url = 'http://localhost:8080/detection/'
    headers = {'charset': 'utf-8'}
    response = requests.post(url, json=data, headers=headers)
    print(response.status_code)

I have already checked several times, what comes by the date, is correct. I tried to call the route by Postman too, and it goes perfectly. I was able to copy and paste the json I sent, and it is correct. However, when I call the route by python, it returns error 400

Answer 1

There is a difference between using the parameter json and the parameter data, maybe you’re confusing the two.

In a POST request, the headers and the "body" of the message are sent. In the case of the use of json or data, the body is nothing more than a string; it turns out that it is a string sent in a different format to one or the other.

In the case of the parameter data, is sent as a form (as if it were your browser after clicking "send") and a header indicating that the body content is of the format x-www-form-urlencoded is automatically added:

In [9]: r = requests.post('https://httpbin.org/anything', data={'foo': 'bar', 'baz': 1337})

In [10]: r.request.body
Out[10]: 'foo=bar&baz=1337'

In [11]: r.request.headers['Content-Type']
Out[11]: 'application/x-www-form-urlencoded'

When you use the parameter json, the requests automatically transforms your body into JSON and adds a header indicating that the body content is of the type JSON:

In [13]: r = requests.post('https://httpbin.org/anything', json={'foo': 'bar', 'baz': 1337})

In [14]: r.request.body
Out[14]: b'{"foo": "bar", "baz": 1337}'

In [15]: r.request.headers['Content-Type']
Out[15]: 'application/json'

Which of the two you will use will depend on the format the API accepts, but bear these differences in mind.