How to "log in" to a website using Python's Requests module?

I know you've found another solution, but for those like me who find this question, looking for the same thing, it can be achieved with requests as follows:

Firstly, as Marcus did, check the source of the login form to get three pieces of information - the url that the form posts to, and the name attributes of the username and password fields. In his example, they are inUserName and inUserPass.

Once you've got that, you can use a requests.Session() instance to make a post request to the login url with your login details as a payload. Making requests from a session instance is essentially the same as using requests normally, it simply adds persistence, allowing you to store and use cookies etc.

Assuming your login attempt was successful, you can simply use the session instance to make further requests to the site. The cookie that identifies you will be used to authorise the requests.

Example

import requests

# Fill in your details here to be posted to the login form.
payload = {
    'inUserName': 'username',
    'inUserPass': 'password'
}

# Use 'with' to ensure the session context is closed after use.
with requests.Session() as s:
    p = s.post('LOGIN_URL', data=payload)
    # print the html returned or something more intelligent to see if it's a successful login page.
    print p.text

    # An authorised request.
    r = s.get('A protected web page url')
    print r.text
        # etc...

If the information you want is on the page you are directed to immediately after login...

Lets call your ck variable payload instead, like in the python-requests docs:

payload = {'inUserName': 'USERNAME/EMAIL', 'inUserPass': 'PASSWORD'}
url = 'http://www.locationary.com/home/index2.jsp'
requests.post(url, data=payload)

Otherwise...

See https://stackoverflow.com/a/17633072/111362 below.

Let me try to make it simple, suppose URL of the site is http://example.com/ and let's suppose you need to sign up by filling username and password, so we go to the login page say http://example.com/login.php now and view it's source code and search for the action URL it will be in form tag something like

 <form name="loginform" method="post" action="userinfo.php">

now take userinfo.php to make absolute URL which will be 'http://example.com/userinfo.php', now run a simple python script

import requests
url = 'http://example.com/userinfo.php'
values = {'username': 'user',
          'password': 'pass'}

r = requests.post(url, data=values)
print r.content

I Hope that this helps someone somewhere someday.