# -*- coding: utf-8 -*-'''Created on 2019年4月27日@author: lenovo'''# import urllib3# def download(url):#     return urllib3.connection_from_url(url)# # print(download('http://now.qq.com'))# 在python中,urllib2被urllib。request所取代# import urllib.request# def download(url):#     return urllib.request.urlopen(url).read()# # print(download('https://baijiahao.baidu.com/s?id=1632775818269407606&wfr=spider&for=pc'))# import urllib.request# def download(url):#     print("Downloading:" + url)#     try:#         html = urllib.request.urlopen(url).read()#     except urllib.request.URLError as e:#         print("Download error:" , e.reason)#         html = None#     return html# # print(download("htp://www.baidu.co"))# import urllib.request# def download(url, num_retries=2):#     try:#         html = urllib.request.urlopen(url).read()#     except urllib.request.URLError as e:#         print("Download error:" , e.reason)#         html = None#         if num_retries > 0 :#             if hasattr(e, "code") and 500 <= e.code < 600 :#                 return download(url, num_retries-1)#     return html#     # # print(download("http://httpstat.us/500"))# print(download("http://www.meetup.com/"))import urllib.requestdef download(url, user_agent="wswp",num_retries=2):    print("Downloading: " , url)    headers = { 'User-agent': user_agent}    request = urllib.request.Request(url, headers=headers)    try:        html = urllib.request.urlopen(request).read()    except urllib.request.URLError as e:        print('Download error:' , e.reason)        html = None        if num_retries > 1 :            if hasattr(e, 'code') and 500 <= e.code < 600:                return download(url, user_agent, num_retries-1)    return htmlprint(download("http://www.meetup.com/"))