Question

我正在尝试从this page中提取信息。该页面一次加载10个项目，我需要滚动以加载所有条目（总共100个）。我能够解析HTML并获取前10个条目所需的信息，但我想在解析HTML之前完全加载所有条目。

我正在使用python，requests和BeautifulSoup。我在使用前10个条目加载页面时解析页面的方式如下：

from bs4 import BeautifulSoup
import requests
s = requests.Session()
r = s.get('https://medium.com/top-100/december-2013')
page = BeautifulSoup(r.text)

但这只会加载前10个条目。所以我查看了页面，得到了用于加载后续条目的AJAX请求，我得到了一个响应，但它是一个时髦的JSON，而我宁愿使用HTML解析器而不是解析JSON。这是代码：

from bs4 import BeautifulSoup
import requests
import json
s = requests.Session()
url = 'https://medium.com/top-100/december-2013/load-more'
payload = {"count":100}
r = s.post(url, data=payload)
page = json.loads(r.text[16:]) #skip some chars that throw json off

这给了我数据，但它是一个非常冗长和复杂的JSON，我宁愿加载页面上的所有数据，只需解析HTML。此外，呈现的HTML提供的信息多于JSON响应（即作者的名称而不是模糊的用户ID等）。有类似的问题here但没有相关的答案。理想情况下，我想进行POST调用，然后请求HTML并解析它，但我还没有能够做到这一点。

Answer 1

当您向下滚动时，您将无法处理请求和BeautifulSoup，因为要提取信息的页面通过JS加载其余条目。您可以使用selenium执行此操作，这会打开一个真实的浏览器，您可以通过编程方式向下传递向下按键事件。观看此视频以查看操作。 http://www.youtube.com/watch?v=g54xYVMojos

http://www.tidbitsofprogramming.com/2014/02/crawling-website-that-loads-content.html

下面是使用selenium提取所有100个帖子的脚本。

import time

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

browser = webdriver.Chrome()

browser.get("https://medium.com/top-100/december-2013")
time.sleep(1)

elem = browser.find_element_by_tag_name("body")

no_of_pagedowns = 20

while no_of_pagedowns:
    elem.send_keys(Keys.PAGE_DOWN)
    time.sleep(0.2)
    no_of_pagedowns-=1

post_elems = browser.find_elements_by_class_name("post-item-title")

for post in post_elems:
    print post.text

输出：

When Your Mother Says She’s Fat
When “Life Hacking” Is Really White Privilege
As tendências culturais dos anos 2000 adiantadas pelo É o Tchan na década de 90
Coming Out as Biracial
Como ganhar discussões com seus parentes de direita neste Natal
How to save local bookstores in two easy steps
Welcome to Dinovember
How to Piss Off Your Barista
The boy whose brain could unlock autism
CrossFit’s Dirty Little Secret
Welcome to Medium
Here’s How the Military Wasted Your Money in 2013
Why I Wear Nail Polish
The day of High School I’ll never forget
7 Reasons Buffalonians Shouldn’t Hate Snow
Dear Guy Who Just Made My Burrito:
Is the Mona Lisa Priceless?
Please stop live tweeting people’s private conversations
Your Friends and Rapists
Eight things you can live without
The Value of Content
40 Ways To Make Life Simple Again
Manila-Beijing-Washington:
Things I Wish Someone Had Told Me When I Was Learning How to Code
Dear Ticketmaster,
Steve Jobs Danced To My Song
11 Things I Wish I Knew When I Started My Business
Bullish: Benevolent Sexism and “That Guy” Who Makes Everything Awkward
Advice to a College Music Student
Silver Gyninen joutui sotaan
Imagining the Post-Antibiotics Future
Which side are you on?
Put it away, junior. 
Casual Predation
The sad little iPhone commercial
How Node.js is Going to Replace JavaScript
Why you should have your heart broken into a million little pieces. 
How to Write Emails Like a CEO
Designing Products That Scale
How radioactive poison became the assassin’s weapon of choice
Why do people hate CrossFit?
We (Still) Need Feminism
10 Advanced Hearthstone Arena Tips
Let It Full-Bleed
What Medium Is For
How a Small Force of Finnish Ski Troops Fought Off a Massive Soviet Army
An Introvert’s Guide to Better Presentations
Mandela The Terrorist
Why You Should have a Messy Desk
Why I’m Not a TEDx Speaker
Fonts have feelings too
You Don’t Want Your Thanksgiving to Go Like This
What I’ve Learned in My First Month as a VC
Why Quantity Should be Your Priority
My Airbnb story
I Wanna Date You Like An Animal
The GIF Guide to Getting Paid
How We Discovered the Underground Chinese App Market
First Images of a Heart Injected with Liquid Metal 
Beyonce Broke the Music Business
“View mode” approach to responsive web design
Sometimes You Will Forget Your Mom Has Cancer
Darkness Ray Beams Invisibility From A Distance
Why Work As We Know It May Be Immoral
Staying Ahead of the Curve
The Geekiest Game Ever Made Has Been Released In Germany 
The Dirty Secret Behind the Salesforce $1M Hackathon
I’m a really good impostor
Mathematical Model of Zombie Epidemics Reveals Two Types of Living-Dead Infections
The Heartbreak Kid
200 Things
I’m Not Racist But—
Duel of the Superbattleships
23 and You
The Seattle NO
I’m a vaccine refuser. There, I said it. 
The Year We Broke Everything
How to make a DIY home alarm system with a raspberry pi and a webcam
Strike While the App is Hot
How to Fall In (and Out) of Love:
Why did Google make an ad for promoting “Search” in India where it has over 97% market share?
A Holiday Message From Jesus
Revealed: The Soviet Union’s $1 Billion ‘Psychotronic’ Arms Race with the US
Postmortem of a Venture-backed Startup
The 1.x Crore Myth
The “Getting Shit Done” Sleep Cycle 
Is the F-35 Joint Strike Fighter the New F-4?
Can the F-35 Win a Dogfight?
Responsive Photosets
Fightball: Millennials vs Boomers
The iconicity of “peaceful resistance”
How We Make Chocolate
Five Ships of the Chinese Navy You Really Ought to Know About
Glassholes and Black Rock City
Bad News for U.S. Warplane Pilots: Russia’s New Dogfighting Missile Can’t Miss
How Antisec Died
10 ways you’ll probably f**k up your startup
UPDATED: Finding the unjustly homeless, and teaching them to code.
Technology hasn’t Changed Us.
What I’ve learned from fatherhood

Answer 2

你可以试试这个：

from selenium import webdriver
from bs4 import BeautifulSoup
from selenium.webdriver.support.ui import WebDriverWait

pause = 10
driver = webdriver.PhantomJS(executable_path='phantomjs.exe')
driver.get("your_url")
#This code will scroll down to the end
while True:
     try:
        # Action scroll down
        driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
     break
 except: 
     pass

Answer 3

或者，您可以尝试安德鲁·切在this question中给出的答案。这是一个有3年历史的问题，页面不再存在，但是如果您尝试使用滚动结果页面进行类似的操作（例如，我搜索了＆＃39; top＆＃39;），您可以找到端点你可以打电话来获取结果列表中的不同页面，在这种情况下是＆＃39; https://medium.com/search/posts?q=top&page=1＆＃39;。

如何一次加载无限滚动中的所有条目以解析python中的HTML

3 个答案: