Staying Logged In Using Requests and Python - python-requests

Question

I am trying to log onto a website using python and requests. I'm pretty sure I am logging on properly. The next part is I go to a different page and try to download a file from that page. However, in order to download the file you have to be logged in. When I go to download the file, however, it redirects me to the log-in menu saying I haven't logged in. I am stuck and don't know what to do! By the way, the website is grabcad.com, what I'm basically trying to do is press the download all button featured on such a page
http://grabcad.com/library/apple-ipod-touch-5th-gen-1
payload = {'member[email]': 'username', 'member[password]': 'pass'}
with requests.Session() as s:
rObject = s.post('http://www.grabcad.com/login', data=payload)
cookies = rObject.cookies
rObject = s.get('http://www.grabcad.com' + downloadUrl, cookies=cookies)
#download URL is something I obtain early and I know it's correct. It's the URL for when you press the downloadAll button
path = 'C:\\User\\Desktop\\filename
with open(path, 'wb') as f:
for chunk in rObject.iter_content():
f.write(chunk)

Answer 1

So I took an altogether different route to solve the problem, I simply used mechanize which is an automated browswer tool for python.
#how to use mechanize to log-in, specifically for grabcad
b.open('http://grabcad.com/login')
b.form = list(b.forms())[1]
control = b.form.find_control("member[email]")
control2 = b.form.find_control("member[password]")
control.value = 'username'
control2.value = 'pass'
b.submit()
#Download Part
path = 'C:\\User\\Desktop\\filename
b.retrieve('https://www.grabcad.com' + downloadUrl, path)
#downloadUrl is obtained earlier and is simply the URL for the download

Answer 2

How are you ensuring that you're logged in correctly? I would print out the html after sending that post request from the session object & ensure it isn't a login page or an invalid password page. Cookies are automatically persistent across requests made on the session object, so I believe that the initial login isn't successful (http://docs.python-requests.org/en/latest/user/advanced/#session-objects).
Personally, I would use selenium for this though.
I have correctly logged into grabcad with the following code:
import requests
s = requests.session()
payload = {'member[email]': 'yourEmail', 'member[password]': 'yourPassword'}
p = s.post('https://grabcad.com/login', data=payload) # Ensure you're posting to HTTPS