Sending a POST request to C# with Python’s requests module

When you send JSON data to C# as a POST request using Python’s Requests module, you may run into a 500 error like the one below.

Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing number

The cause is the JSON. To send JSON data via POST with the Requests module, you need to do it like this:

data = {
  "id": id,
  "no": no
}

headers = {'Content-Type': 'application/x-www-form-urlencoded; charset=utf-8'}

response = requests.post(url="http://xxx.com/aaa/api/aaa.aspx", json=data, headers=headers)

When calling post, you have to send the data through the json parameter so that C#’s JSON library doesn’t throw a parsing error!