Requests

The Incoming Letter

Every time your browser visits a website, it sends a letter to the server. This letter is called an HTTP request. Just like a real letter, it has three parts:

1. The Request Line (the envelope)

The very first line tells the server what you want:

GET /about HTTP/1.1

GET -- the method (what you want to do)
/about -- the path (which page you want)
HTTP/1.1 -- the version (which "language" to speak)

2. The Headers (the sticky notes)

After the first line come the headers -- extra notes attached to the letter:

Host: example.com
Accept: text/html
User-Agent: Mozilla/5.0

Each header is a name and a value, separated by a colon. They tell the server things like "I'm a browser" or "I prefer HTML."

3. The Body (the letter inside)

Some requests carry data -- like a form you filled out. The body comes after a blank line:

POST /login HTTP/1.1
Host: example.com
Content-Type: application/json

{"username": "alice", "password": "secret"}

GET requests usually have no body. POST requests usually do.

Query Parameters

Sometimes you put extra info right in the URL:

GET /search?q=pokemon&page=2 HTTP/1.1

The ?q=pokemon&page=2 part is the query string. PyWeb parses it into a dictionary: {"q": "pokemon", "page": "2"}.

How PyWeb Parses a Request

from pyweb.request import parse_request

raw = "GET /search?q=pokemon HTTP/1.1\r\nHost: example.com\r\n\r\n"
request = parse_request(raw)

request.method       # "GET"
request.path         # "/search"
request.headers      # {"Host": "example.com"}
request.query_params # {"q": "pokemon"}
request.body         # ""

What We Test

GET, POST, PUT, DELETE methods parse correctly.
Headers are parsed as name-value pairs.
POST bodies are captured.
Query strings are split into parameters.
Malformed requests raise clear errors.

Next Up

The server has read the letter. Now it needs to write a reply! Head to Responses.