What is the difference between the 'json' and 'data' parameters in Requests?

The requests library in Python allows you to send HTTP requests using methods like get, post, put, delete, etc. Two of the parameters that you can use when sending requests are json and data. These parameters are used to specify the content that you want to send to the server. Here's the difference between them:

data parameter:

• Usage: The data parameter is used when you want to send form-encoded data (content type application/x-www-form-urlencoded) to the server. This is the kind of data that is typically sent from HTML forms.
• Format: When using the data parameter, you can pass a dictionary, a list of tuples, or a bytes object. If you pass a dictionary or a list of tuples, requests will form-encode it for you.

• Example:

  import requests
  
  payload = {'key1': 'value1', 'key2': 'value2'}
  
  # Dictionary payload
  r = requests.post('https://httpbin.org/post', data=payload)
  print(r.text)
  
  # List of tuples payload
  payload_tuples = [('key1', 'value1'), ('key2', 'value2')]
  r = requests.post('https://httpbin.org/post', data=payload_tuples)
  print(r.text)
  
  # Bytes payload
  payload_bytes = 'key1=value1&key2=value2'.encode('utf-8')
  r = requests.post('https://httpbin.org/post', data=payload_bytes)
  print(r.text)
  

json parameter:

• Usage: The json parameter is used when you want to send JSON data to the server. The content type for this request will be set to application/json.
• Format: When using the json parameter, you should pass a JSON-serializable Python object (usually a dictionary). requests will automatically serialize the Python object to JSON.

• Example:

  import requests
  
  payload = {'key1': 'value1', 'key2': 'value2'}
  
  # JSON payload
  r = requests.post('https://httpbin.org/post', json=payload)
  print(r.text)
  

When you use the json parameter, requests sets the Content-Type header to application/json and serializes the Python object to a JSON string. On the other hand, when you use the data parameter with a dictionary or list of tuples, the Content-Type header is set to application/x-www-form-urlencoded, and the dictionary or list of tuples is encoded as a form submission.

It's important to choose the right parameter based on the API you're interacting with and the format it expects for the request data.