session = requests.Session()
with open('my_file.csv', 'rb') as f:
    form = encoder.MultipartEncoder({'documents': ('my_file.csv', f,
        'application/octet-stream'), 'composite': 'NONE'})
headers = {'Prefer': 'respond-async', 'Content-Type': form.content_type}
resp = session.post(url, headers=headers, data=form)
python requests upload large file with additional data