How to make a post request with the Python requests library?

Question

I am using the following filters in Postman to make a POST request in a Web API but I am unable to make a simple POST request in Python with the requests library.

First, I am sending a POST request to this URL (http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets) with the following filters in Postman applied to the Body, with the raw and JSON(application/json) options selected.

Filters in Postman

{
  "filter": {
    "filters": [
      {
        "field": "RCA_Assigned_Date",
        "operator": "gte",
        "value": "2017-05-31 00:00:00"
      },
      {
        "field": "RCA_Assigned_Date",
        "operator": "lte",
        "value": "2017-06-04 00:00:00"
      },
      {
        "field": "T_Subcategory",
        "operator": "neq",
        "value": "Temporary Degradation"
      },
      {
        "field": "Issue_Status",
        "operator": "neq",
        "value": "Queued"
      }],
     "logic": "and"
    }
}

The database where the data is stored is Cassandra and according to the following links Cassandra not equal operator, Cassandra OR operator, Cassandra Between order by operators, Cassandra does not support the NOT EQUAL TO, OR, BETWEEN operators, so there is no way I can filter the URL with these operators except with AND.

Second, I am using the following code to apply a simple filter with the requests library.

import requests
payload = {'field':'T_Subcategory','operator':'neq','value':'Temporary Degradation'}
url = requests.post("http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets",data=payload)

But what I've got is the complete data of tickets instead of only those that are not temporary degradation.

Third, the system is actually working but we are experiencing a delay of 2-3 mins to see the data. The logic goes as follows: We have 8 users and we want to see all the tickets per user that are not temporary degradation, then we do:

def get_json():
    if user_name == "user 001":
        with urllib.request.urlopen(
    "http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets?user_name=user&001",timeout=15) as url:
            complete_data = json.loads(url.read().decode())

    elif user_name == "user 002":
        with urllib.request.urlopen(             
    "http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets?user_name=user&002",timeout=15) as url:
            complete_data = json.loads(url.read().decode())
    return complete_data

def get_tickets_not_temp_degradation(start_date,end_date,complete_):
    return Counter([k['user_name'] for k in complete_data if start_date < dateutil.parser.parse(k.get('DateTime')) < end_date and k['T_subcategory'] != 'Temporary Degradation'])

Basically, we get the whole set of tickets from the current and last year, then we let Python to filter the complete set by user and so far there are only 10 users which means that this process is repeated 10 times and makes me no surprise to discover why we get the delay...

My questions is how can I fix this problem of the requests library? I am using the following link Requests library documentation as a tutorial to make it working but it just seems that my payload is not being read.

Answer 1

Your Postman request is a JSON body. Just reproduce that same body in Python. Your Python code is not sending JSON, nor is it sending the same data as your Postman sample.

For starters, sending a dictionary via the data arguments encodes that dictionary to application/x-www-form-urlencoded form, not JSON. Secondly, you appear to be sending a single filter.

The following code replicates your Postman post exactly:

import requests

filters = {"filter": {
    "filters": [{
        "field": "RCA_Assigned_Date",
        "operator": "gte",
        "value": "2017-05-31 00:00:00"
    }, {
        "field": "RCA_Assigned_Date",
        "operator": "lte",
        "value": "2017-06-04 00:00:00"
    }, {
        "field": "T_Subcategory",
        "operator": "neq",
        "value": "Temporary Degradation"
    }, {
        "field": "Issue_Status",
        "operator": "neq",
        "value": "Queued"
    }],
    "logic": "and"
}}

url = "http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets"
response = requests.post(url, json=filters)

Note that filters is a Python data structure here, and that it is passed to the json keyword argument. Using the latter does two things:

• Encode the Python data structure to JSON (producing the exact same JSON value as your raw Postman body value).
• Set the Content-Type header to application/json (as you did in your Postman configuration by picking the JSON option in the dropdown menu after picking raw for the body).

requests is otherwise just an HTTP API, it can't make Cassandra do any more than any other HTTP library. The urllib.request.urlopen code sends GET requests, and are trivially translated to requests with:

def get_json():
    url = "http://10.61.202.98:8081/T/a/api/rows/cat/ect/tickets"
    response = requests.get(url, params={'user_name': user}, timeout=15)    
    return response.json()

I removed the if branching and replaced that with using the params argument, which translates a dictionary of key-value pairs to a correctly encoded URL query (passing in the user name as the user_name key).

Note the json() call on the response; this takes care of decoding JSON data coming back from the server. This still takes long, you are not filtering the Cassandra data much here.