获取gai和套接字错误，我不确定这两个错误是什么意思

Question

我正在使用我在github上找到的一个程序，从我用csv下载的excel电子表格中的网站列表中抓取电子邮件。运行它时会出现以下错误：

    Cannot retrive URL: 
Traceback (most recent call last):
  File "/usr/lib/python3.5/urllib/request.py", line 1254, in do_open
    h.request(req.get_method(), req.selector, req.data, headers)
  File "/usr/lib/python3.5/http/client.py", line 1107, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib/python3.5/http/client.py", line 1152, in _send_request
    self.endheaders(body)
  File "/usr/lib/python3.5/http/client.py", line 1103, in endheaders
    self._send_output(message_body)
  File "/usr/lib/python3.5/http/client.py", line 934, in _send_output
    self.send(msg)
  File "/usr/lib/python3.5/http/client.py", line 877, in send
    self.connect()
  File "/usr/lib/python3.5/http/client.py", line 849, in connect
    (self.host,self.port), self.timeout, self.source_address)
  File "/usr/lib/python3.5/socket.py", line 694, in create_connection
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
  File "/usr/lib/python3.5/socket.py", line 733, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -5] No address associated with hostname

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "pagescanner.py", line 39, in parseAddress
    website = urllib2.urlopen(getAddress(url))
  File "/usr/lib/python3.5/urllib/request.py", line 163, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python3.5/urllib/request.py", line 466, in open
    response = self._open(req, data)
  File "/usr/lib/python3.5/urllib/request.py", line 484, in _open
    '_open', req)
  File "/usr/lib/python3.5/urllib/request.py", line 444, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.5/urllib/request.py", line 1282, in http_open
    return self.do_open(http.client.HTTPConnection, req)
  File "/usr/lib/python3.5/urllib/request.py", line 1256, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [Errno -5] No address associated with hostname>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "pagescanner.py", line 85, in <module>
    main()
  File "pagescanner.py", line 71, in main
    execute()
  File "pagescanner.py", line 60, in execute
    parseAddress(s)
  File "pagescanner.py", line 51, in parseAddress
    print ("Cannot retrive URL: ") + err.reason[1]
TypeError: 'gaierror' object does not support indexing

下面是我使用的代码

import sys
try:
    import urllib.request as urllib2
except ImportError:
    import urllib2
import re
import csv

list1 = []
list2 = []
list3 = []

def addList():
    with open('file.csv', 'rt') as f:
        reader = csv.reader(f)
        for row in reader:
            for s in row:
                list2.append(s)

def getAddress(url):
    http = "http://"
    https = "https://"

    if http in url:
        return url
    elif https in url:
        return url
    else:
        url = "http://" + url
        return url

def parseAddress(url):
    global list3
    try:
        website = urllib2.urlopen(getAddress(url))
        html = website.read()

        addys = re.findall('''[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?''', html, flags=re.IGNORECASE)

        global list1
        list1.append(addys)

    except urllib2.HTTPError as err:
        print ("Cannot retrieve URL: HTTP Error Code: "), err.code
        list3.append(url)
    except urllib2.URLError as err:
        print ("Cannot retrive URL: ") + err.reason[1]
        list3.append(url)

def execute():
    global list2
    addList()
    totalNum = len(list2)
    atNum = 1
    for s in list2:
        parseAddress(s)
        print ("Processing ") + str(atNum) + (" out of ") + str(totalNum)
        atNum = atNum + 1

    print ("Completed. Emails parsed: ") + str(len(list1)) + "."


### MAIN

def main():
    global list2
    execute()
    global list1
    myFile = open("finishedFile.csv", "w+")
    wr = csv.writer(myFile, quoting=csv.QUOTE_ALL)
    for s in list1:
        wr.writerow(s)
    myFile.close
    global list3
    failFile = open("failedSites.csv", "w+")
    write = csv.writer(failFile, quoting=csv.QUOTE_ALL)
    for j in list3:
        write.writerow(j)
    failFile.close

main()

我假设这与我试图将代码从python2转换为python3有关，但我被难住了。

Answer 1

如果是URL错误，则可能是您正在尝试解析Excel电子表格中的无效地址，因此显示这些URL会很有帮助。如果是套接字错误，您可以尝试通过使用socket类解析URL并获取主机名来解决此问题：

import socket
ipAdd = socket.gethostbyname(url)   # Retrieves URL's IP address (example: 'www.google.com'
website = urllib2.urlopen(getAddress(ipAdd))  # Formats to http:// or https://
html = website.read()  # Gets HTML code

如果这不起作用，您可能需要安装Flask，这是一个Web应用程序框架，旨在充当套接字(用于服务器和应用程序之间的通信)。Python3.5及更高版本、Python2.7和PyPi都支持它：

$ pip install Flask