A dropbox read only client

dropbox_getfile.py

#coding:utf-8
import os
import dropbox

app_key = 'app_key'
app_secret = 'app_secret'


def load_access_token():
    if os.path.isfile("access_token"):
        with open("access_token") as f:
            access_token = f.read().strip()
        return access_token


def login():
    flow = dropbox.client.DropboxOAuth2FlowNoRedirect(app_key, app_secret)
    authorize_url = flow.start()
    print '1. Go to: ' + authorize_url
    print '2. Click "Allow" (you might have to log in first)'
    print '3. Copy the authorization code.'
    code = raw_input("Enter the authorization code here: ").strip()
    access_token, user_id = flow.finish(code)
    with open("access_token", "w") as f:
        f.write(access_token)
    return access_token

client = None
def get_client(access_token=None):
    global client

    if access_token:
        client = dropbox.client.DropboxClient(access_token)

    if not client:
        access_token = load_access_token()
        if not access_token:
            access_token = login()
        client = get_client(access_token)

    return client


def get_file(path):
    try:
        response = get_client().get_file(path)
    except dropbox.rest.ErrorResponse as e:
        if 401 == e.status:
            print "Access token expired, login again"
            access_token = login()
            client = get_client(access_token)
            response = client.get_file(path)
    return response


def get_file_content(path):
    response = get_file(path)
    return response.read()


def main():
    print get_file_content('/Documents/test_file.txt')

    response = get_file('/Documents/test_file.txt')
    line_num = 1
    while True:
        line = response.readline()
        print "# %d:" % line_num, line
        line_num += 1
        if not line:
            break

if __name__ == '__main__':
    main()