Python reptans et output

2024-07-12

1. Python crawler and output example

Infra exemplum est simplicis telae reptans in Pythone scriptae quae certam interretialem paginam repere (exempli gratia dicamushttps://example.com sed nota quod in usu actuali cum titulo (Titulo) rei paginae realis quae reptare permittitur oportet nos reponere) et imprimere. Cum protinus accessiones et radentes paginas reales involvere possunt quaestiones iuris et iuris, solum exemplum rationis hic praebemus.

Ad hoc negotium utemur Pythonisrequestsbibliothecam mittere HTTP petitiones et ususBeautifulSoup Bibliothecam ad parse HTML content. Si has bibliothecas nondum instituimus, eas per pituitam instituere possumus:


bash复制代码
pip install requests beautifulsoup4

Exemplar hic codicis integri est:


# 导入必要的库  
import requests  
from bs4 import BeautifulSoup  
  
def fetch_website_title(url):  
    """  
    抓取指定网页的标题并返回。  
      
    参数:  
    url (str): 需要抓取的网页的URL。  
      
    返回:  
    str: 网页的标题，如果抓取失败则返回None。  
    """  
    try:  
        # 发送HTTP GET请求  
        response = requests.get(url)  
          
        # 检查请求是否成功  
        if response.status_code == 200:  
            # 使用BeautifulSoup解析HTML内容  
            soup = BeautifulSoup(response.text, 'html.parser')  
              
            # 查找网页的<title>标签  
            title_tag = soup.find('title')  
              
            # 如果找到<title>标签，则返回其内容  
            if title_tag:  
                return title_tag.get_text(strip=True)  
            else:  
                return "No title found."  
        else:  
            return f"Failed to retrieve the webpage. Status code: {response.status_code}"  
    except requests.RequestException as e:  
        return f"Error fetching the webpage: {e}"  
  
# 示例URL（请替换为我们要抓取的网页的URL）  
url = 'https://example.com'  
  
# 调用函数并打印结果  
title = fetch_website_title(url)  
print(f"The title of the webpage is: {title}")

Notice：

(I) Obhttps://example.comexempli gratia possessor est, ergo necesse est cum valida pagina URL reponere quae reptans cum currit permittit.

(II) Reptile debet parere exigentiis scopo website cum curritrobots.txtDocumentum de ius proprietatis et adeundi restrictiones loci stipulatur.

(3) Aliquot paginas possunt habere machinationes anti-repatas, ut perscriptio User-Agens, limites frequentiae, etc. Rogationem nostram capitis modificare necesse est (utUser-Agent) vel modi ut procuratores ad has restrictiones praeterire.

(4.) Plures paginae interretiales structuras vel graviores notitias exigentias capere, necesse est ut plus discere de HTML, CSS selectoribus, XPath et retis postulationibus discere possimus.

2. Plura exempla codice

Infra exemplum codicis Pythonis accuratioris est, hoc tempore utarrequestsbibliothecam mittere HTTP petitiones et ususBeautifulSoupbibliothecam ad parse HTML contenta perrepere a situ reali (exempli gratia utimurhttps://www.wikipedia.orgExempli gratia, sed nota quod ipsae serpere debet parere cum scriptoris paginaerobots.txtpraescripta et librariae consilium).

Primum fac nos instituisserequestsetbeautifulsoup4 Bibliotheca. Si non installatur, pituitam utere ut eam instituam;


bash复制代码
pip install requests beautifulsoup4

Sequente codice uti possumus capto ac titulo Vicipaediae paginam imprimere:


# 导入必要的库  
import requests  
from bs4 import BeautifulSoup  
  
def fetch_and_parse_title(url):  
    """  
    发送HTTP GET请求到指定的URL，解析HTML内容，并返回网页的标题。  
  
    参数:  
    url (str): 需要抓取的网页的URL。  
  
    返回:  
    str: 网页的标题，如果抓取或解析失败则返回相应的错误消息。  
    """  
    try:  
        # 发送HTTP GET请求  
        headers = {  
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36'  
        }  # 设置User-Agent来模拟浏览器访问  
        response = requests.get(url, headers=headers)  
  
        # 检查请求是否成功  
        if response.status_code == 200:  
            # 使用BeautifulSoup解析HTML内容  
            soup = BeautifulSoup(response.text, 'html.parser')  
  
            # 查找网页的<title>标签  
            title_tag = soup.find('title')  
  
            # 提取并返回标题内容  
            if title_tag:  
                return title_tag.get_text(strip=True)  
            else:  
                return "No title found in the webpage."  
        else:  
            return f"Failed to retrieve the webpage. Status code: {response.status_code}"  
    except requests.RequestException as e:  
        return f"Error fetching the webpage: {e}"  
  
# 示例URL（这里使用Wikipedia的主页作为示例）  
url = 'https://www.wikipedia.org'  
  
# 调用函数并打印结果  
title = fetch_and_parse_title(url)  
print(f"The title of the webpage is: {title}")

Hoc signum primum petit caput (headersquae continet aUser-Agent campum, hoc est accessum navigatoris verum simulare, quod paginae aliquae petendi caput reprehendo ne aditus repens. Inde petitionem GET cum domicilio designato et BeautifulSoup utitur ad parse contentum HTML redditum.Deinde spectat pro HTML<title> tag et extrahere eius textum contentum sicut titulus paginae interreti. Titulum denique ad consolatorium imprimit.

Quaeso note quod licet hoc exemplum Vicipaediae utatur exemplo, in re vera semper scopo inhaerere debemusrobots.txtdocumenta et ius operae ad invigilandum exercitia nostra reptilia legalia et ethica sunt.

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