iT 邦幫忙技術文章爬蟲，新增到 postgres

ithome_crawler_2.py

import requests
from bs4 import BeautifulSoup
from datetime import datetime
import re
import psycopg2

host = "localhost"
user = "postgres"
dbname = "ithome2019"
password = "<server_admin_password>"
conn_string = f'host={host} user={user} dbname={dbname} password={password}'
conn = psycopg2.connect(conn_string)
print('資料庫連線成功！')

cursor = conn.cursor()

def crawl_list():
    """爬取文章列表頁
    """
    # 抓取 1~10 頁
    for page in range(1, 11):
        html_doc = requests.get(f'https://ithelp.ithome.com.tw/articles?tab=tech&page={page}').text
        soup = BeautifulSoup(html_doc, 'lxml')

        # 先找到文章區塊
        article_tags = soup.find_all('div', class_='qa-list')

        # 沒有文章
        if len(article_tags) == 0:
            # 跳出換頁迴圈或離開程式
            print('沒有文章了！')
            break

        for article_tag in article_tags:
            # 再由每個區塊去找文章連結
            title_tag = article_tag.find('a', class_='qa-list__title-link')
            article_url = title_tag['href']

            crawl_content(article_url)

def crawl_content(url):
    """爬取文章內容

    :param url: 文章連結
    """
    html_doc = requests.get(url).text
    soup = BeautifulSoup(html_doc, 'lxml')

    leftside = soup.find('div', class_='leftside')
    original_post = leftside.find('div', class_='qa-panel')

    article_header = original_post.find('div', class_='qa-header')
    article_info = article_header.find('div', class_='ir-article-info__content')

    # 標題
    title = article_header.find('h2', class_='qa-header__title').get_text(strip=True)

    # 作者
    author = article_info.find('a', class_='ir-article-info__name').get_text(strip=True)

    # 發文時間
    published_time_str = article_info.find('a', class_='ir-article-info__time').get_text(strip=True)
    published_time = datetime.strptime(published_time_str, '%Y-%m-%d %H:%M:%S')

    # 文章標籤
    tag_group = article_header.find('div', class_='qa-header__tagGroup')
    tags_element = tag_group.find_all('a', class_='tag')
    tags = [tag_element.get_text(strip=True) for tag_element in tags_element]

    # 內文
    content = original_post.find('div', class_='markdown__style').get_text(strip=True)

    # 瀏覽數
    view_count_str = article_info.find('div', class_='ir-article-info__view').get_text(strip=True)
    view_count = int(re.search('(\d+).*', view_count_str).group(1))

    article = {
        'url': url,
        'title': title,
        'author': author,
        'publish_time': published_time,
        'tags': ','.join(tags),
        'content': content,
        'view_count': view_count
    }
    article_id = insert_article(article)
    
    crawl_response(article_id, soup)

def crawl_response(article_id, soup):
    """爬取文章回應
    
    :param article_id: 文章 ID，作為外來鍵
    :param soup: 因為跟原文跟回應在同一個畫面，這邊偷懶直接用文章的 soup 物件
    """
    leftside = soup.find('div', class_='leftside')
    responses = leftside.find_all('div', class_='response')

    results = []

    for response in responses:
        panel = response.find('div', class_='qa-panel__content')
        header = panel.find('div', class_='response-header__info')

        result = {'article_id': article_id}

        # 回文作者
        result['author'] = header.find('a', class_='response-header__person').get_text(strip=True)

        # 回應時間
        time_str = header.find('a', class_='ans-header__time').get_text(strip=True)
        result['publish_time'] = datetime.strptime(time_str, '%Y-%m-%d %H:%M:%S')

        # 回文內容
        result['content'] = panel.find('div', class_='markdown__style').get_text(strip=True)

        results.append(result)
        
    insert_responses(results)
	
def insert_article(article):
    """把文章插入到資料庫中

    :param article: 文章資料
    
    :return: 文章 ID
    :rtype: int
    """
    cursor.execute('''
    INSERT INTO public.ithome_article(title, url, author, publish_time, tags, content, view_count)
    VALUES (%(title)s,%(url)s,%(author)s,%(publish_time)s,%(tags)s,%(content)s,%(view_count)s)
    RETURNING id;
    ''',
    article)

    print(f'[{article["title"]}] 新增成功！')

    conn.commit()
    
    return cursor.fetchone()[0]
    
def insert_responses(responses):
    """把回文插入到資料庫中

    :param responses: 回文資料
    """
    for response in responses:
        cursor.execute('''
        INSERT INTO public.ithome_response(article_id, author, publish_time, content)
        VALUES (%(article_id)s,%(author)s,%(publish_time)s,%(content)s);
        ''',
        response)

    conn.commit()

if __name__ == '__main__':
    crawl_list()
	
cursor.close()
conn.close()