Initialising a python script to access Dropbox

dropbox_client.py

#!/usr/bin/python
# 
# This is a simple script for setting up the dropbox api.
# It can be used as the basis for a more complex script.
# The file ~/.dropbox.cfg is where you store the oauth authorisation
# tokens. It has the following format:
#
#
#	[AppName]
#	
#	app_key = <XYZZY>
#	app_secret = <XYZZY>
#	
#	access_key = <XYZZY>
#	access_secret = <XYZZY>
#
# You shouldn't define the access_key or access_secret values
# initially, the script will prompt the user to visit the dropbox
# website in order to authorise the app, and then write the values
# to the file.
#
# This was written quickly to start using the Dropbox API in a simple
# script. I'm putting it on Github so I can refer to it in future.
#
# Brett Hutley <brett@hutley.net>

import sys, os
from ConfigParser import SafeConfigParser
from optparse import OptionParser
from dropbox import client, rest, session

optp = OptionParser()
optp.add_option("-c", "--config", dest="config_file", metavar="FILE",
                default= os.path.join(os.path.expanduser("~"), ".dropbox.cfg"),
                help="dropbox configuration file")
optp.add_option("-a", "--app", dest="app", default="MyApp",
                help="Application config to use.")

opts, args = optp.parse_args()

if not os.path.exists(opts.config_file):
    error("config file '%s' doesn't exist" % opts.config_file)
    exit(1)

config_parser = SafeConfigParser()
config_parser.read(opts.config_file)

app_key = config_parser.get(opts.app, 'app_key')
app_secret = config_parser.get(opts.app, 'app_secret')

access_type = 'dropbox'  # should be 'dropbox' or 'app_folder' as configured for your app

sess = session.DropboxSession(app_key, app_secret, access_type)

access_key = None
access_secret = None

try:
    access_key = config_parser.get(opts.app, 'access_key')
    access_secret = config_parser.get(opts.app, 'access_secret')
except:
    pass

if access_key is None or access_secret is None:
    request_token = sess.obtain_request_token()

    url = sess.build_authorize_url(request_token)
    print "url:", url
    print "Please visit this website and press the 'Allow' button, then hit 'Enter' here."
    raw_input()

    access_token = sess.obtain_access_token(request_token)

    access_key = access_token.key
    access_secret = access_token.secret

    cfg_file = open(opts.config_file, 'a+')
    cfg_file.write("access_key = %s\n" % (access_key, ))
    cfg_file.write("access_secret = %s\n" % (access_secret, ))
    cfg_file.close()

sess.set_token(access_key, access_secret)
client = client.DropboxClient(sess)