和xpath選取器比起來,感覺CSS選取器容易一些,跟寫.css時方法基本一樣,就是在擷取內容時和xpath不同,這裡需要注意一下.
這裡介紹如何用css選取器提取出一篇文章的資料
提取的資料跟xpath那篇文章內容相同
之前xpath中我們擷取元素是通過.entry-header h1::text,如果是屬性則用.entry-header a::attr(href)
介紹一個常用的函數extract_first()
相當於extract()[0],但是extract()[0]當數組沒有元素時,也就是沒有擷取到資料時會出錯,所以用extract_first()方法,也可以加上需要返回的內容,比如空,extract_first("")
title = response.css(".entry-header h1::text").extract_first()#p可以不加create_date = response.css("p.entry-meta-hide-on-mobile::text").extract()[0].strip().replace('·','').strip()#擷取點贊數praise_nums = response.css('#110287votetotal::text').extract()[0]#擷取收藏數fav_nums = response.css('.btn-bluet-bigger.href-style.bookmark-btn .register-user-only::text ').extract()[0].strip()match_re = re.match('.*?(\d+).*',fav_nums)if match_re: #擷取收藏數 fav_nums = match_re.group(1)comment_nums = response.css('.btn-bluet-bigger.href-style.hide-on-480::text').extract()[0].strip()match_re = re.match('.*?(\d+).*',fav_nums)if match_re: comment_nums = match_re.group(1)tag_list = response.css('.entry-meta-hide-on-mobile a::text').extract()content = response.css('div.entry').extract()[0]tag_list = [element for element in tag_list if not element.strip().endswith('評論')]tag = ','.join(tag_list)
當我們要選擇的屬性名稱字有多個時比如下面:
這市在選擇時應該用
post_urls = response.css('#archive .post.floated-thumb .post-thumb a::attr(href)').extract()
也就是.post.floated-thumb應該連起來,或者唯寫.floated-thumb 完整代碼(准)
def parse_detail(self, response): title = response.css(".entry-header h1::text").extract_first() create_date = response.css("p.entry-meta-hide-on-mobile::text").extract()[0].strip().replace("·","").strip() praise_nums = response.css(".vote-post-up h10::text").extract()[0] fav_nums = response.css(".bookmark-btn::text").extract()[0] match_re = re.match(".*?(\d+).*", fav_nums) if match_re: fav_nums = int(match_re.group(1)) else: fav_nums = 0 comment_nums = response.css("a[href='#article-comment'] span::text").extract()[0] match_re = re.match(".*?(\d+).*", comment_nums) if match_re: comment_nums = int(match_re.group(1)) else: comment_nums = 0 content = response.css("div.entry").extract()[0] tag_list = response.css("p.entry-meta-hide-on-mobile a::text").extract() tag_list = [element for element in tag_list if not element.strip().endswith("評論")] tags = ",".join(tag_list) pass