使用多线程优化python脚本[关闭]

Question

大家好！我已经编写了小型网页爬虫功能。但我是多线程的新手，我无法优化它。我的代码是：

alreadySeenURLs = dict() #the dictionary of already seen crawlers
candidates = set() #the set of URL candidates to crawl

def initializeCandidates(url):

    #gets page with urllib2
    page = getPage(url)

    #parses page with BeautifulSoup
    parsedPage = getParsedPage(page)

    #function which return all links from parsed page as set
    initialURLsFromRoot = getLinksFromParsedPage(parsedPage)

    return initialURLsFromRoot 

def updateCandidates(oldCandidates, newCandidates):
    return oldCandidates.union(newCandidates)

candidates = initializeCandidates(rootURL)

for url in candidates:

    print len(candidates)

    #fingerprint of URL
    fp = hashlib.sha1(url).hexdigest()

    #checking whether url is in alreadySeenURLs
    if fp in alreadySeenURLs:
        continue

    alreadySeenURLs[fp] = url

    #do some processing
    print url

    page = getPage(url)
    parsedPage = getParsedPage(page, fix=True)
    newCandidates = getLinksFromParsedPage(parsedPage)

    candidates = updateCandidates(candidates, newCandidates)

可以看出，这里它在特定时间从候选人那里获取一个网址。我想让这个脚本成为多线程的，以这样一种方式，它可以从候选人那里获取至少 N 个 url，并完成这项工作。谁能指导我？提供任何链接或建议？

Answer 1

你可以从这两个链接开始：

1. Python中线程的基本参考 http://docs.python.org/library/threading.html

2. 他们在 python 中实际实现多线程 URL 爬虫的教程 http://www.ibm.com/developerworks/aix/library/au-threadingpython/

另外，你已经有一个python爬虫：http://scrapy.org/