利用requests、正则表达式和Beautiful爬取贴吧用户名、评论和图片
定义工具类——去除爬取项多余内容
class Tool():
removeImg = re.compile('<img.*?>|｛7｝| ') # 去除img标签，1-7位空格，
removeAddr = re.compile('<a.*?>|</a>') # 删除超链接标签
replaceLine = re.compile('<tr>|<div>|</div>|</p>') # 把换行的标签换位\n
replaceTD = re.compile('<td>') # 把表格制表<td>换为\t
replaceBR = re.compile('<br><br>|<br>|</br>|</br></br>') # 把换行符或者双换行符换为\n
removeExtraTag = re.compile('.*?') # 把其余标签剔除
removeNoneLine = re.compile('\n+') # 把多余空行删除
def replace(self, x):
x = re.sub(self.removeImg, "", x)
x = re.sub(self.removeAddr, "", x)
x = re.sub(self.replaceLine, "\n", x)
x = re.sub(self.replaceTD, "\t", x)
x = re.sub(self.replaceBR, "\n", x)
x = re.sub(self.removeExtraTag, "", x)
x = re.sub(self.removeNoneLine, "\n", x)
return x.strip() # 把strip()前后多余内容删除
帖子标题、页数都可以在第一个链接页面找到相关数据，图片等也是直接用正则表达式进行获取
class Spider():
def __init__(self):
self.tool = Tool()
# 获取源码
def getSource(self, url):
user_agents = ['Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20130406 Firefox/23.0',
'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/20100101 Firefox/18.0',
'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533+ \(KHTML, like Gecko) Element Browser 5.0',
'IBM WebExplorer /v0.94', 'Galaxy/1.0 [en] (Mac OS X 10.5.6; U; en)',
'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)',
'Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14',
'Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) \Version/6.0 Mobile/10A5355d Safari/8536.25',
'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) \Chrome/28.0.1468.0 Safari/537.36',
'Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0; Trident/5.0; TheWorld)']
# user_agent在一堆范围中随机获取
# random.randint()获取随机数，防止网站认出是爬虫而访问受限
index = random.randint(0, 9)
user_agent = user_agents[index]
headers = {'User_agent': user_agent}
html = requests.get(url, headers=headers)
return html.text
# 获取帖子标题
def getTitle(self, url):
result = self.getSource(url)
pattern = re.compile('<h1.*?title.*?>(.*?)</h1>', re.S)
items = re.search(pattern, result)
print('这篇帖子标题为：', self.tool.replace(items.group(1)))
# 获取帖子总页数
def getPageNumber(self, url):
result = self.getSource(url)
pattern = re.compile('<ul.*?l_posts_num.*?<span class="red">(.*?)</span>', re.S)
items = re.search(pattern, result).group(1)
print('帖子共有', items, '页')
return items
def getContent(self, url):
result = self.getSource(url)
pattern = re.compile('<a data-field.*?p_author_name.*?">(.*?)</a>.*?<div id="post_content_.*?>(.*?)</div>',
re.S)
items = re.findall(pattern, result)
# 获取楼层数可以直接用循环，省去正则匹配的麻烦
number = 1
for item in items:
# item[0]为楼主，item[1]为发言内容，使用\n换行符打出内容更干净利落
# item[1]中可能有img链接，用自定义Tool工具清洗
print('\n', number, '楼', '\n楼主：', item[0], '\n内容:', self.tool.replace(item[1]))
time.sleep(0.01)
number += 1
# 获取晒图,清洗获得链接并保存入list
def getImage(self, url):
result = self.getSource(url)
soup = BeautifulSoup(result, 'lxml')
# 此处用BeautifulSoup显然更高效
# find_all()返回一个list,find()返回一个元素
# 注意class属性和python内置的重合，所以加_变成class_
items = soup.find_all('img', class_="BDE_Image")
images = []
number = 0
for item in items:
print('发现一张图，链接为:', item['src'])
images.append(item['src'])
number += 1
if number >= 1:
print('\n', '共晒图', number, '张，厉害了我的哥！！！')
else:
print('喏，没有图......')
return images
创建目录进行图片保存
# 创建目录
def makeDir(self, path):
self.path = path.strip()
# E = os.path.exists(os.path.join(os.getcwd(), self.path))
E = os.path.exists(self.path)
if not E:
# 创建新目录,若想将内容保存至别的路径（非系统默认），需要更环境变量
# 更改环境变量用os.chdir()
# os.makedirs(os.path.join(os.getcwd(), self.path))
os.mkdir(self.path)
# os.chdir(os.path.join(os.getcwd(), self.path))
print('正在创建名为', self.path, '的文件夹')
return self.path
else:
print('名为', self.path, '的文件夹已经存在...')
return False
def saveImage(self, detailURL, name):
try:
data = requests.get(detailURL, timeout=10).content
# 保存文件，一定要用绝对路径 `
# 所以设置self.path，是为了方便后面函数无障碍调用
except requests.exceptions.ConnectionError:
print('下载图片失败')
return None
fileName = name + '.' + 'jpg'
fileName = os.path.join(self.path, name+'.jpg')
f = open(fileName, 'wb')
f.write(data)
f.close()
print('成功保存图片', fileName)
获取所有页面——主要代码逻辑
def getAllPage(self):
self.siteURL = 'http://tieba.baidu.com/p/5862596971'
# 获取帖子标题
self.getTitle(self.siteURL)
# 获取帖子页数
numbers = self.getPageNumber(self.siteURL)
for page in range(1, int(numbers) + 1):
# 格式化索引链接
self.url = self.siteURL + '?pn=' + str(page)
print('\n\n', '正准备获取第', page, '页的内容...')
# 获取评论
print('\n', '正准备获取评论...')
self.getContent(self.url)
# 每一页创建一个文件
self.makeDir(path='page' + str(page))
# 获取图片
print('\n', '正准备获取图片...')
images = self.getImage(self.url)
print('\n', '正准备保存图片...')
number = 1
# 保存图片，先从之前的list中找链接
for detailURL in images:
name = 'page' + str(page) + '_'+'num' + str(number)
self.saveImage(detailURL, name)
time.sleep(0.1)
number += 1
print('\n\n', '完成第', page, u'页')
print('\n\n', '恭喜，圆满成功！')
- 代码过程中对于用户名中含有特殊符号(图片)的会直接返回链接，改良中
- 更多爬虫代码详情参考Githun
