Build your own Website

1. Browsers make requests to a given url (http://enginehere.com/sample/)
2. The URL is broken down into parts (protocol, hostname, and path)
3. Hostname is converted into an IP address for a computer connected to the internet (server).  The browser and server connect.
4. The server runs a program to return the resource based on the path (/sample/ in this case).   The program can be Python, Ruby, etc.

The server program returns the resource at the given path as a response to the browser

The response is just a string (HTML, images, video, etc)

The browser renders this content on the screen

In our Python scripts, we often asked for user input

When websites want user input, they use forms

Forms submit data to servers via requests

GET vs. POST

from some_fake_module import hit_dbfrom another_fake_module import render
def handle_hello(request):     greeting = request.POST.get("greet")     person = request.POST.get("person")     we_know_them = False     if person and greeting:         # hit database and confirm that we know this person         we_know_them = hit_db(person)         if we_know_them:             template = "my_template_name.html"             html = render(template, {"person": person, "greeting": greeting})             return html     else:              return "We do not know you"

HTTP is stateless, meaning each request is independent

To keep track of users (i.e. facebook), we need to preserve state

We use a combination of Cookies and databases

Cookies are strings sent by servers to browsers (and vice versa) on each request and can be used to identify a user

  # from the command line pip install the web server library  sudo pip install lpthw.web

import web

urls = (
  '/', 'index'
)

app = web.application(urls, globals())

class index:
    def GET(self):
        greeting = "Hello World"
        return greeting

## If you run this module directly (python this_module.py), then run code block
if __name__ == "__main__":
    app.run() 

When you run this script, it will start a server at the address:

http://localhost:8080  (same as http://127.0.0.1:8080)

Finish these on your own

You have the knowledge to do it!

And wherever you come up short, dive deep with internet searches (Stack Overflow especially)

The final exercises tell you to set up Nginx or Apache

These are classic web servers that you can deploy to machines on the cloud (you've just run local servers so far)

These servers, in turn, run Django Ruby on Rails, Node.js, or other web frameworks

If you are adventurous, you can set this up on AWS

Or you can just use Heroku