python select

##socket非阻塞

import socket
from urllib.parse import urlparse

def get_url(url):
    url=urlparse(url)
    host=url.netloc
    path=url.path
    if not path:
        path="/"
    print(host, path)
    client=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    client.setblocking(False)
    try:
        client.connect((host, 80))
    except BlockingIOError as e:
        pass
    while True:
        try:
            client.send("'GET {} HTTP/1.1\r\nHost: {}:{}\r\nConnection: close\r\n\r\n'".format(path,host,80).encode('utf8'))
            break
        except OSError as e:
            continue
    data=b""
    while True:
        try:
            d=client.recv(1024)
        except BlockingIOError as e:
            continue
        if d:
            data+=d
        else:
            break
    print(data.decode('utf8'))
    client.close()
get_url("http://www.baidu.com")

##select
import socket
from urllib.parse import urlparse
from selectors import DefaultSelector,EVENT_WRITE,EVENT_READ
selector=DefaultSelector()
urls=["http://www.baidu.com"]
stop=False
class Fetcher:
    def get_url(self,url):
        self.parseUrl=url
        url = urlparse(url)
        self.data=b""
        self.host = url.netloc
        self.path = url.path
        if not self.path:
            self.path = "/"
        self.client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.client.setblocking(False)
        try:
            self.client.connect((self.host, 80))
        except BlockingIOError as e:
            pass
        selector.register(self.client.fileno(),EVENT_WRITE,self.connected)
    def readAble(self,key):
        d = self.client.recv(1024)
        if d:
            self.data += d
        else:
            selector.unregister(self.client.fileno())
            print(self.data.decode('utf8'))
            self.client.close()
            urls.remove(self.parseUrl)
            if not urls:
                global stop
                stop=True
    def connected(self,key):
        selector.unregister(key.fd)
        self.client.send( "'GET {} HTTP/1.1\r\nHost: {}:{}\r\nConnection: close\r\n\r\n'".format(self.path, self.host, 80).encode('utf8'))
        selector.register(self.client.fileno(),EVENT_READ,self.readAble)


def loop():
    while not stop:
        status=selector.select()
        for key,master in status:
            call_back=key.data
            call_back(key)
if __name__=="__main__":
    #fetcher=Fetcher()
    for url in range(20):
        url="https://www.baidu.com/s?wd=%s"%url
        urls.append(url)
        fetcher = Fetcher()
        fetcher.get_url(url)
    loop()