This is an example script to get the list of articles on your instapaper account. You need to ask Instapaper for xauth access and you (or your user) need to be an instapaper subscriber ($3 a month) to be able to see the API.

instapaper_xauth

from __future__ import unicode_literals
from urlparse import parse_qs
import requests
from requests_oauthlib import OAuth1

key = "key"
secret ="secret"

oauth = OAuth1(key, secret)

instaaccount = "username"
instapassword = "password"

params = {}
params["x_auth_username"] = instaaccount
params["x_auth_password"] = instapassword
params["x_auth_mode"] = 'client_auth'

request_token_url = 'https://www.instapaper.com/api/1/oauth/access_token'

r = requests.post(url=request_token_url, auth=oauth, data=params)
credentials = parse_qs(r.content)
oauth_token = credentials.get('oauth_token')[0]
oauth_secret = credentials.get('oauth_token_secret')[0]

oauth = OAuth1(key, secret+"&"+oauth_secret, oauth_token)
list_url = 'https://www.instapaper.com/api/1/bookmarks/list'
params = {
    "username": instaaccount,
    "password": instapassword
}
r = requests.post(list_url, auth=oauth, data=params)