How to simulate a button click in a request?

问题

Please do not close this question - this is not a duplicate. I need to click the button using Python requests, not Selenium, as here

I am trying to scrape Reverso Context translation examples page. And I have a problem: I can get only 20 examples and then I need to click the "Display more examples" button lots of times while it exists on the page to get the full results list. It can simply be done using a web browser, but how can I do it with Python Requests library?

I looked at the button's HTML code, but I couldn't find an onclick attribute to look at JS script attached to it, and I don't understand what request I need to send:

<button id="load-more-examples" class="button load-more " data-default-size="14px">Display more examples</button>

And here is my Python code:

from bs4 import BeautifulSoup
import requests
import re


with requests.Session() as session:  # Create a Session
    # Log in
    login_url = 'https://account.reverso.net/login/context.reverso.net/it?utm_source=contextweb&utm_medium=usertopmenu&utm_campaign=login'
    session.post(login_url, "Email=reverso.scraping@yahoo.com&Password=sample",
           headers={"User-Agent": "Mozilla/5.0", "content-type": "application/x-www-form-urlencoded"})

    # Get the HTML
    html_text = session.get("https://context.reverso.net/translation/russian-english/cat", headers={"User-Agent": "Mozilla/5.0"}).content

    # And scrape it
    for word_pair in BeautifulSoup(html_text).find_all("div", id=re.compile("^OPENSUBTITLES")):
        print(word_pair.find("div", class_="src ltr").text.strip(), "=", word_pair.find("div", class_="trg ltr").text.strip())

Note: you need to log in, otherwise it will show only first 10 examples and will not show the button. You may use this real authentication data:
E-mail: reverso.scraping@yahoo.com
Password: sample

回答1:

Here is a solution that gets all the example sentences using requests and removes all the HTML tags from them using BeautifulSoup:

from bs4 import BeautifulSoup
import requests
import json


headers = {
    "Connection": "keep-alive",
    "Accept": "application/json, text/javascript, */*; q=0.01",
    "X-Requested-With": "XMLHttpRequest",
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36",
    "Content-Type": "application/json; charset=UTF-8",
    "Content-Length": "96",
    "Origin": "https://context.reverso.net",
    "Sec-Fetch-Site": "same-origin",
    "Sec-Fetch-Mode": "cors",
    "Referer": "https://context.reverso.net/^%^D0^%^BF^%^D0^%^B5^%^D1^%^80^%^D0^%^B5^%^D0^%^B2^%^D0^%^BE^%^D0^%^B4/^%^D0^%^B0^%^D0^%^BD^%^D0^%^B3^%^D0^%^BB^%^D0^%^B8^%^D0^%^B9^%^D1^%^81^%^D0^%^BA^%^D0^%^B8^%^D0^%^B9-^%^D1^%^80^%^D1^%^83^%^D1^%^81^%^D1^%^81^%^D0^%^BA^%^D0^%^B8^%^D0^%^B9/cat",
    "Accept-Encoding": "gzip, deflate, br",
    "Accept-Language": "ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7",
}

data = {
    "source_text": "cat",
    "target_text": "",
    "source_lang": "en",
    "target_lang": "ru",
    "npage": 1,
    "mode": 0
}

npages = requests.post("https://context.reverso.net/bst-query-service", headers=headers, data=json.dumps(data)).json()["npages"]
for npage in range(1, npages + 1):
    data["npage"] = npage
    page = requests.post("https://context.reverso.net/bst-query-service", headers=headers, data=json.dumps(data)).json()["list"]
    for word in page:
        print(BeautifulSoup(word["s_text"]).text, "=", BeautifulSoup(word["t_text"]).text)

At first, I got the request from the Google Chrome DevTools:

Pressed F12 key to enter it and selected the Network Tab
Clicked the "Display more examples" button
Found the last request ("bst-query-service")
Right-clicked it and selected Copy > Copy as cURL (cmd)

Then, I opened this online-tool, insert the copied cURL to the textbox on the left and copied the output on the right (use Ctrl-C hotkey for this, otherwise it may not work).

After that I inserted it to the IDE and:

Removed the cookies dict - it is not necessary here
Important: Rewrote the data string as a Python dictionary and wrapped it with json.dumps(data), otherwise, it returned a request with empty words list.
Added a script, that: gets a number of times to fetch the words ("pages") and created a for loop that gets words this number of times and prints them without HTML tags (using BeautifulSoup)

UPD:
For those, who visited the question to learn how to work with Reverso Context (not just to simulate a button click request on other website) there is a Python wrapper for Reverso API released: Reverso-API. It can do the same thing as above but much simpler:

from reverso_api.context import ReversoContextAPI


api = ReversoContextAPI("cat", "", "en", "ru")
for source, target in api.get_examples_pair_by_pair():
    print(highlight_example(source.text), "==", highlight_example(target.text))

来源：https://stackoverflow.com/questions/60353109/how-to-simulate-a-button-click-in-a-request

标签

python

web-scraping

beautifulsoup

python-requests

urllib