Python爬取国外天气预报网站的方法

本文实例讲述了Python爬取国外天气预报网站的方法。分享给大家供大家参考。具体如下：

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)

#"<h6><a href="http://www.accuweather.com/zh/browse-locations/afr"><em>Africa</em></a></h6>"

pattern = "<h6><a href="(.*)"><em>(.*)</em></a></h6>"

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("n".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:CourseNLP_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("<ul id="country-breadcrumbs">") != -1:

start = count

opened = True

if opened and line.find("</ul>") != -1:

end = count

opened = False

count = count + 1

return "n".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 = "<span class="cond">(.*?)</span>"

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("n".join(locations.keys()))

fp.close()

fp = open("conditions.fr", "w")

fp.write("n".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。