some question about PartI-"downloading web page"

[zhang14725804]

def request(url):

   # wrong code
    scheme,url = url.split("://",1)
    assert scheme in ["http","https"],"Unknown scheme {}".format(scheme)
    port = 80 if scheme =="http" else 443
    if scheme == "https":
        ctx = ssl.create_default_context()
        s = ctx.wrap_socket(s,server_hostname=host)
    if ":" in host:
        host,port = host.split(":",1)
        port=int(port)

    assert url.startswith("http://")
    url = url[len("http://"):]
    host,path = url.split("/",1)
    path = "/"+path

    s = socket.socket(
        family=socket.AF_INET,
        type=socket.SOCK_STREAM,
        proto=socket.IPPROTO_TCP,
    )

    s.connect(("example.org",80))

    s.send(b"GET /index.html HTTP/1.0\r\n"+b"Host: example.org\r\n\r\n")
    response = s.makefile("r",encoding="utf8",newline="\r\n")

    statusline = response.readline()
    version,status,explanation=statusline.split(" ",2)
    assert status == "200","{}:{}".format(status,explanation)

    headers = {}
    while True:
        line = response.readline()
        if line =="\r\n":break
        header,value = line.split(":",1)
        headers[header.lower()]=value.strip()

    body = response.read()
    s.close()
    return headers,body

question1: my code is wrong about ssl part. What`s the right way to add ssl, and how to test ssl

question2:Exercises is difficult for me, how and where to get the answer about Exercises

[shuhei]

For the question 1, a socket needs to be created before you wrap it with SSL (actually TLS). So,

    s = socket.socket(
        family=socket.AF_INET,
        type=socket.SOCK_STREAM,
        proto=socket.IPPROTO_TCP,
    )

should come before:

    if scheme == "https":
        ctx = ssl.create_default_context()
        s = ctx.wrap_socket(s,server_hostname=host)

[shuhei]

For the question 2, there are people who published their browser implementations based on this book. You might find solutions to some exercises. https://github.com/search?l=Python&q=browser.engineering&type=Repositories

[zhang14725804]

thank you very much. Thank you for your sincere help

[pavpanchekha]

Uh oh, I assign those exercises in class. Gotta keep in mind there are already exercise solutions around!

[pavpanchekha]

(For this reason we're not planning to make "official" exercise solutions public, though I would like to refactor my test suites for them and make those public.)