Python 3.5 Function to upload a pdf as "transient doc" to Adobe Sign via REST V5

upload_transient.py

import requests  # get requests via pip with documentation here: http://docs.python-requests.org/en/master/

def upl_trans(file_path, docName, apiToken):
    """Uploads document to EchoSign and returns its ID
    :param access_token: EchoSign Access Token
    :param file_path: Absolute or relative path to File
    :return string: transientDucumentId
    :usage example:   transID1 = upl_trans('./_MSA_noline.pdf','Test1.pdf', '*** your_api_token_or_integration_key_here ***')
    """
    headers = {
        'Access-Token': apiToken,  # Your access token or integration key here.
    }
    data = {
        'Mime-Type': 'application/pdf',
        'File-Name': docName
    }
    url = config01.tranUrl
    files = {'File': open(file_path, 'rb')}
    return requests.post(url, headers=headers, data=data,
                         files=files).json().get('transientDocumentId')