Python爬取国外天气预报网站的方法

crawl_weather.py如下：

#encoding=utf-8
import httplib
import urllib2
import time
from threading import Thread
import threading
from Queue import Queue
from time import sleep
import re
import copy
lang = "fr"
count = 0
class Location:
 # Location(False, "中国", "北京", "zh")
 # Location(True, "", "亚洲", "zh")
 def __init__(self, is_beyond_country, country_name, loc_name, lang):
 self.country_name = country_name
 self.loc_name = loc_name
 self.lang = lang
 self.is_beyond_country = is_beyond_country
prn_lock = threading.RLock()
def GetLocationURLs(url, recursive):
 global count
 if url.find("weather-forecast") != -1:
 count = count + 1
 if count % 500 == 0:
 prn_lock.acquire()
 print "count:%d" % (count)
 prn_lock.release()
 return [url]
 page = urllib2.urlopen(url).read()
 time.sleep(0.01)
 #"
Africa
"
 pattern = "
(.*)
"
 locs = re.findall(pattern, page)
 locs = [(url, name) for url, name in locs if url.find("browse-locations") != -1 or url.find("weather-forecast") != -1]
 if not recursive:
 urls = [url for url, name in locs]
 return urls
 urls = []
 for _url, _name in locs:
 lst = GetLocationURLs(_url, True)
 urls.extend(lst)
 return urls
#entry_url = "http://www.accuweather.com/zh/browse-locations"
entry_url = "http://www.accuweather.com/%s/browse-locations/eur/fr" % (lang)
#regions = ["afr", "ant", "arc", "asi", "cac", "eur", "mea", "nam", "ocn", "sam"]
#regions = ["eur"]
#region_urls = [ "%s/%s" % (entry_url, reg) for reg in regions]
#region_urls = ["http://www.accuweather.com/zh/browse-locations/eur/fr"]
sub_urls = GetLocationURLs(entry_url, False)
print len(sub_urls)
print sub_urls
q = Queue()
location_urls = []
ThreadNum = 5
lock = threading.RLock()
for url in sub_urls:
 q.put(url)
def working():
 while True:
 url = q.get()
 lst = GetLocationURLs(url, True)
 print "%s %d urls " % (url, len(lst))
 lock.acquire()
 location_urls.extend(lst)
 lock.release()
 q.task_done()
for i in range(ThreadNum):
 t = Thread(target=working)
 t.setDaemon(True)
 t.start()
q.join() 
fp = open('locations.txt', "w")
fp.write("
".join(location_urls))
fp.close()
#for url in location_urls:
# print url
#location_urls = GetLocationURLs(entry_url)
'''
def Fetch(url):
 try:
 print url
 web_path = url[0]
 local_name = url[1] 
 print "web_path:", web_path
 print "local_name:", local_name
 sContent = urllib2.urlopen(web_path).read()
 savePath = "D:\Course\NLP_Manning\%s" % (local_name)
 print savePath
 file = open(savePath,'wb')
 file.write(sContent)
 file.close()
 print savePath + " saved";
 except:
 pass;
def working():
 while True:
 url = q.get()
 Fetch(url)
 sleep(10)
 q.task_done()
#root_url = "https://class.coursera.org/nlp/lecture/index?lecture_player=flash"
root_url = "https://class.coursera.org/nlp/lecture/index?lecture_player=flash"
page = urllib2.urlopen(root_url).read()
for i in range(NUM):
 t = Thread(target=working)
 t.setDaemon(True)
 t.start()
urls = copy.deepcopy(ppt_urls)
urls.extend(srt_urls)
urls.extend(video_urls)
print len(ppt_urls)
print len(srt_urls)
print len(video_urls)
print len(urls)
for url in urls:
 q.put(url)
q.join()
'''
'''
root_url = "http://www.accuweather.com/zh/cn/andingmen/57494/weather-forecast/57494"
page = urllib2.urlopen(root_url).read()
print page
'''

FetchLocation.py如下：

#encoding=utf-8
import sys
import httplib
import urllib2
import time
from threading import Thread
import threading
from Queue import Queue
from time import sleep
import re
import copy
from xml.dom import minidom
import HTMLParser
import datetime
q = Queue()
locks = [threading.RLock() for i in range(2)]
ThreadNumber = 20
locations = {}
conds = {}
def FindCountryBreadCrumbs(page):
 lines = page.splitlines()
 count = 0
 start = -1
 opened = False
 for line in lines:
 if line.find("") != -1:
 start = count
 opened = True
 if opened and line.find("") != -1:
 end = count
 opened = False
 count = count + 1
 return "
".join(lines[start: (end + 1)])
def GetText(nodelist):
 rc = []
 for node in nodelist:
 if node.nodeType == node.TEXT_NODE:
 rc.append(HTMLParser.HTMLParser().unescape(node.data))
 return ''.join(rc)
def FindCondition(page):
 pat = "(.*?)"
 cds = re.findall(pat, page)
 cds = [HTMLParser.HTMLParser().unescape(cd).encode("utf-8") for cd in cds]
 return cds 
def ExtractInfo(url):
 try:
 page = urllib2.urlopen(url).read()
 except Exception, e:
 return []
 text = FindCountryBreadCrumbs(page)
 text = HTMLParser.HTMLParser().unescape(text)
 dom = minidom.parseString(text.encode("utf-8"))
 locs = []
 lis = dom.getElementsByTagName("li")
 for li in lis:
 adr_list = li.getElementsByTagName("a")
 if adr_list:
 locs.append(GetText(adr_list[0].childNodes).encode("utf-8"))
 strs = li.getElementsByTagName("strong")
 if strs:
 locs.append(GetText(strs[0].childNodes).encode("utf-8"))
 cds = FindCondition(page)
 return locs, cds
def AddMap(lst, m):
 for x in lst:
 if m.get(x) == None:
 m[x] = 1
def working():
 while True:
 urls = q.get()
 #print len(urls)
 m = {}
 m2 = {}
 count = 0
 for url in urls:
 count = count + 1
 #print "%d/%d" % (count, len(urls))
 locs, cds = ExtractInfo(url)
 AddMap(locs, m)
 AddMap(cds, m2)
 locks[1].acquire()
 AddMap(m.keys(), locations)
 AddMap(m2.keys(), conds)
 locks[1].release()
 q.task_done()
def main():
 if len(sys.argv) < 2:
 exit()
 loc_path = sys.argv[1]
 fp = open(loc_path, "r")
 urls = [line.strip() for line in fp]
 fp.close()
 #urls = urls[0:1000]
 blocks = len(urls) / ThreadNumber + 1
 for start in range(0, len(urls), blocks):
 end = start + blocks
 if end > len(urls):
 end = len(urls)
 q.put(urls[start:end])
 for i in range(ThreadNumber):
 t = Thread(target=working)
 t.setDaemon(True)
 t.start()
 q.join()
 fp = open("location_name.fr", "w")
 fp.write("
".join(locations.keys()))
 fp.close()
 fp = open("conditions.fr", "w")
 fp.write("
".join(conds.keys()))
 fp.close()
if __name__ == '__main__':
 main()

希望本文所述对大家的python程序设计有所帮助。