python - 使用 Python 请求抓取页面

Question

我在网页抓取方面遇到了一些问题，这是我的代码:

from bs4 import BeautifulSoup

import requests
import re
import csv
import argparse

def save_csv_file(filename, array):
    with open(filename, 'wb') as f:
        writer = csv.writer(f)
        writer.writerow(["item_name","item_price","item_category"])
        writer.writerows(array)

def process_data(name, price, category):

    item_name = name.text if name else 'NA'
    item_price = price.text if price else 'NA'
    item_category = category.text if category else 'NA'

    item_name = item_name.replace(" ", "").replace("\r\n", "").replace("\n", "").encode("utf-8")
    item_price = item_price.replace(" ", "").replace("\r\n", "").replace("\n", "").encode("utf-8")
    item_category = item_category.replace(" ", "").replace("\r\n", "").replace("\n", "").encode("utf-8")

    return (item_name, item_price, item_category)

def do_scrap(filename, url, payload, headers):

    # Request the URL with parameters and headers
    r = requests.post(url, payload, headers = headers, allow_redirects = True)

    if(r.status_code == 200):

        # Save response content in html variable
        html = r.content

        # Parsed html variable into HTML file with bs4
        parsed_html = BeautifulSoup(html, "html.parser")

        # Print document title
        print parsed_html.head.find('title').text

        # Find all of the HTML elements which are describing hotels
        tables = parsed_html.find_all("a", {"class" : "result-link"})

        # Print the numbers of the hotels
        print "Found %s records." % len(tables)

        # Empty helpers
        items = []
        count = 0

        # Looping the HTML elements and print properties for each hotel
        for table in tables:
            name = table.find("h3", {"class" : "result-title"})
            price = table.find("p", {"class" : "price text-truncate"})
            category = table.find("p", {"class" : "merchant-name text-truncate"})

            items.append(process_data(name, price, category))
        count += 1

        if count > 0:
            # Save array with data to csv file
            save_csv_file(filename = filename, array = items)

            # Print end of job info
            print "\n%s records downloaded and saved to %s." % (count, filename)
    else:
        print "Code error: %s" % r.status_code

if __name__ == '__main__':

ap = argparse.ArgumentParser()

ap.add_argument("-p","--product",required=True,help="Product name")
ap.add_argument("-c","--category",default="",help="Product category")

args = vars(ap.parse_args())

product = args['product']
category = args['category']

payload = {
    'siteSearchQuery':product,
    'from':'colibri'
}

headers = {
    'Host':'www.kelkoo.co.uk',
    'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
    'Accept-Encoding':'gzip, deflate, sdch',
    'Accept-Language':'pl-PL,pl;q=0.8,en-US;q=0.6,en;q=0.4',
    'Upgrade-Insecure-Requests':'1',
    'User-Agent':'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36'
}

url = "http://www.kelkoo.co.uk/ctl/do/search"

filename = "%s_co_uk_kelkoo_data.csv" % product

do_scrap(
    filename=filename,
    url=url,
    payload=payload,
    headers=headers)

在这个请求之后，我得到的结果与我给出的结果不同:

www.kelkoo.co.uk/ctl/do/search?siteSearchQuery=nokia+130&from=colibri

进入我的网络浏览器，是什么导致了这个问题？是不是跟页面重定向什么的有关？

Answer 1

我可以看到多种因素会导致您得到不同的结果:

• 您启动了 POST 而不是 GET。为 requests.get 查找 params。
• 他们使用 javascript 修改页面。