python爬虫（爬取蜂鸟网图片）_创建文件夹

import requests,urllib,os
from bs4 import BeautifulSoup

ans = 1

for page in range(58,69):
    url = 'http://bbs.fengniao.com/forum/pic/slide_101_6478020_768937' + str(page) + '.html'
    header = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.109 Safari/537.36'}
    source_code = requests.get(url,headers = header)
    plain_text = source_code.text

    soup = BeautifulSoup(plain_text,'lxml')

    download_link = []
    file_name = ''
    for pic_tag in soup.find_all('a'):        
        #get the name
        if pic_tag.get('href')=='/forum/6478020.html':
            file_name = pic_tag.get('title')
        
        if pic_tag.get('class')==['pictureDownload']:
            download_link.append(pic_tag.get('href'))

    #file setting
    folder_path = "D:/spider_things/2016.4.6/" + file_name +"/"
    if not os.path.exists(folder_path):
       os.makedirs(folder_path)

    for item in download_link:
        urllib.urlretrieve(item,folder_path + str(ans) + '.jpg')
        print 'download_',ans,'_pics'
        ans=ans+1

这次爬虫应用了创建文件夹的功能：

    #file setting
    folder_path = "D:/spider_things/2016.4.6/" + file_name +"/"
    if not os.path.exists(folder_path):
       os.makedirs(folder_path)

上面代码块的意思是：
"os.path.exists(folder_path)"用来判断folder_path这个路径是否存在，如果不存在，就执行“os.makedirs(folder_path)”来创建这个路径