Question

我正在处理我的第一个Web爬虫，并且由于stackoverflow的帮助，我设法将以下代码放在一起。这段代码可以很好地单击每个页面，然后进入每个链接以提取我需要的信息。但是，由于没有要提取的网络信息，它卡在了其中一个链接上。

import pandas as pd
import requests
from bs4 import BeautifulSoup
from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
from selenium.webdriver.firefox.firefox_binary import FirefoxBinary
from selenium.webdriver.common.keys import Keys
from selenium.common.exceptions import NoSuchElementException
import time

binary = FirefoxBinary('geckodriver.exe')
driver = webdriver.Firefox()
driver.get('http://www.interzum.com/exhibitors-and-products/exhibitor-index/exhibitor-index-15.php')

url = 'http://www.interzum.com/exhibitors-and-products/exhibitor-index/exhibitor-index-15.php'
text = requests.get(url).text
page1 = BeautifulSoup(text, "html.parser")

def get_data(url, tries=0, max_tries=3):
    text_test2 = requests.get(url).text
    page2 = BeautifulSoup(text_test2, "html.parser")

    try:
        title = page2.find('h1', attrs={'class':'hl_2'}).text    
        content = page2.find('div', attrs={'class':'cont'}).text
        phone = page2.find('div', attrs={'class':'sico ico_phone'}).text
        email_div = page2.find('div', attrs={'class':'sico ico_email'})
        email = email_div.find('a', attrs={'class': 'xsecondarylink'})['href']

    web_div = page2.find('div', attrs={'class':'sico ico_link'})
    web = web_div.find('a', attrs={'class':'xsecondarylink'})
    if web != None:
        web = web['href']

    except:
        if tries < max_tries:
            tries += 1
            print("try {}".format(tries))
            return get_data(url, tries)


    data = {'Name': [title],
            'Street address': [content], 
            'Phone number': [phone],
            'Email': [email],
            'Web': [web]            
            }

    return pd.DataFrame(data=data)

df = pd.DataFrame()
for i in range(0,80):
    print(i)
    page1 = BeautifulSoup(driver.page_source, 'html.parser')


    for div in page1.findAll('div', attrs={'class':'item'}):

        for a in div.findAll('a', attrs={'class':'initial_noline'}):
            if 'kid=' not in a['href'] : continue
            print('http://www.interzum.com' + a['href'])

            data = get_data('http://www.interzum.com' + a['href'])
            df = pd.concat([df, data])

    next_button = driver.find_element_by_class_name('slick-next')
    next_button.click()
    time.sleep(20)

df.to_csv('results.csv')

我尝试了许多不同的方法来尝试说，如果网络不存在，则继续循环播放，如果确实存在，则将我拉到href上。但是我不断收到一条错误消息 UnboundLocalError：赋值之前引用了本地变量'web'

我似乎无法将其与网络上的信息正确地整合在一起。对我做错了什么的任何见解将不胜感激！

谢谢大家。

Answer 1

我认为您需要切换到硒来从特定页面检索信息，因为并非总是为请求加载内容。您可以将以下内容用作框架。

import requests
from bs4 import BeautifulSoup as bs
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

driver = webdriver.Chrome()
baseLink = 'http://www.interzum.com'
varLink = 'http://www.interzum.com/exhibitors-and-products/exhibitor-index/exhibitor-index-15.php?fw_goto=aussteller/blaettern&fw_ajax=1&paginatevalues=%7B%22stichwort%22%3A%22%22%7D&start={}&dat=231518http://www.interzum.com/exhibitors-and-products/exhibitor-index/exhibitor-index-15.php'
startUrl = 'http://www.interzum.com/exhibitors-and-products/exhibitor-index/exhibitor-index-15.php'
resultsPerPage = 20
i = 0
headers = {'User-Agent' : 'Mozilla/5.0'}
results = []
final = []
with requests.Session() as s:
    r = s.get(startUrl, headers = headers)
    soup = bs(r.content, 'lxml')
    numPages = int(soup.select('a[rel=next]')[-2].text)
    links = list((baseLink + link['href'] for link in soup.select('[href*="fw_goto=aussteller/details&&kid="]')))
    results.append(links)
    for j in range(1, numPages):
        i+=20
        url = varLink.format(i)
        r = s.get(url, headers = headers)
        soup = bs(r.content, 'lxml')
        links = list((baseLink + link['href'] for link in soup.select('[href*="fw_goto=aussteller/details&&kid="]')))
        results.append(links)

    totalList = [item for sublist in results for item in sublist]

    for link in totalList:
        driver.get(link)
        try:
            title = driver.find_element_by_css_selector('h1.hl_2').text    
            content = driver.find_element_by_css_selector('div.cont').text
            phone = driver.find_element_by_css_selector('div.sico.ico_phone').text
            email = driver.find_element_by_css_selector('div.sico.ico_email a.xsecondarylink').get_attribute('href')
            web = driver.find_element_by_css_selector('div.sico.ico_link a.xsecondarylink').get_attribute('href')
            final.append([title, content, phone, email, web])
        except Exception as e:
            print(link)
            print(e)
            continue

美丽的汤-提取不在每个循环页面上的网站链接时出错

1 个答案: