I'm trying to send username and password data from a web form to my server.
The password is sent as plain text over a https connection, then properly encrypted on the server (using python hashlib.sha224) before being stored, however I'm not sure how to transmit the password text to the server in an encrypted format.
My web client is written in javascript, and the server is written in python.
The HTTPS channel over which you send the password to the server provides encryption that is good enough.
However, you need a more secure storage mechanism for the password. Use an algorithm like "bcrypt" with many thousands of hash iterations (bcrypt calls this the cost factor, and it should be at least 16, meaning 216 iterations), and a random "salt". This works by deriving an encryption key from the password, which is a computationally expensive process, then using that key to encrypt some known cipher text, which is saved for comparison on future login attempts.
Also, using HTTPS on the login only is not sufficient. You should use it for any requests that require an authenticated user, or that carry an authentication cookie.
How to encrypt password sent to server