#通過非阻塞io實現http請求

import socket
from urllib.parse import urlparse


#使用非阻塞io完成http請求

def get_url(url):
    #通過socket請求html
    url = urlparse(url)
    host = url.netloc
    path = url.path
    if path == "":
        path = "/"

    #建立socket連線
    client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    client.setblocking(False)		# 這裡設定成非阻塞
    try:
        client.connect((host, 80)) # 阻塞不會消耗cpu
    except BlockingIOError as e:
        pass

    #不停的詢問連線是否建立好， 需要while迴圈不停的去檢查狀態
    #做計算任務或者再次發起其他的連線請求

    while True:
        try:
            client.send("GET {} HTTP/1.1\r\nHost:{}\r\nConnection:close\r\n\r\n".format(path, host).encode("utf8"))
            break
        except OSError as e:
            pass


    data = b""
    while True:
        try:
            d = client.recv(1024)
        except BlockingIOError as e:
            continue
        if d:
            data += d
        else:
            break

    data = data.decode("utf8")
    html_data = data.split("\r\n\r\n")[1]
    print(html_data)
    client.close()

if __name__ == "__main__":
    get_url("http://www.baidu.com")