Python snippet to invoke HTTP Post request with file attached(multipart/form-data) in the body of the request. This function returns Response object.

PostFileAttachment.py

# importing the requests library
import requests

def postFileAttachment(url,fileName,contentType):
   """Sends a POST request.
  :param url: URL for the new :class:`Request` object.
  :param fileName: File to be sent/attached in the body of the request.
  :return: :class:`Response <Response>` object.
  """
  multipart = MultipartEncoder(
    fields={'field1': ('filename', open(fileName, 'rb'), contentType)}
  )
  response = requests.post(url, data=multipart,headers={'Content-Type': multipart.content_type})
  return response