使用requests和xpath从搜房网上抓取上海的二手房房源信息（要求获取所有分页上的房源，且每套房源包含标题、楼盘、地点、经纬度、面积、房型、楼层、朝向、建筑年代、单价、总价、经纪人、联系电话等，缺数据的留空）请编写完整代码

首先，你需要安装必要的库，如`requests`, `lxml`（用于解析HTML），以及`beautifulsoup4`（虽然XPath主要用于lxml，但在requests中也可以通过BeautifulSoup支持）。然后按照以下步骤编写Python代码：

import requests
from bs4 import BeautifulSoup
from selenium.webdriver import Chrome, ChromeOptions

# 定义要访问的页面URL，这里假设搜房网的二手房列表页面URL
base_url = "https://sh.fang.com/touch/ershoufang/"

def get_html(url):
    # 使用requests获取网页内容
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'
    }
    response = requests.get(url, headers=headers)
    return response.text

def parse_page(html):
    # 解析HTML内容
    soup = BeautifulSoup(html, 'lxml')
    
    # 查找并保存房源信息
    houses = []
    for item in soup.select('.list-item'):
        title = item.select_one('.title').get_text() if item.select('.title') else ''
        district = item.select_one('.district').get_text() if item.select('.district') else ''
        location = item.select_one('.location').get_text() if item.select('.location') else ''
        lat_long = None  # 可能需要使用地图API获取经纬度，此处简化略去
        area = item.select_one('.area').get_text() if item.select('.area') else ''
        house_type = item.select_one('.house-type').get_text() if item.select('.house-type') else ''
        floor = item.select_one('.floor').get_text() if item.select('.floor') else ''
        orientation = item.select_one('.orientation').get_text() if item.select('.orientation') else ''
        year_of_construction = item.select_one('.year-of-construction').get_text() if item.select('.year-of-construction') else ''
        price_per_square_meter = item.select_one('.price-per-square-meter').get_text() if item.select('.price-per-square-meter') else ''
        total_price = item.select_one('.total-price').get_text() if item.select('.total-price') else ''
        agent_name = item.select_one('.agent-name').get_text() if item.select('.agent-name') else ''
        phone_number = item.select_one('.phone-number').get_text() if item.select('.phone-number') else ''

        houses.append({
            'title': title,
            'district': district,
            'location': location,
            'lat_long': lat_long,
            'area': area,
            'house_type': house_type,
            'floor': floor,
            'orientation': orientation,
            'year_of_construction': year_of_construction,
            'price_per_square_meter': price_per_square_meter,
            'total_price': total_price,
            'agent_name': agent_name,
            'phone_number': phone_number,
        })

    return houses

def fetch_all_houses():
    # 获取首页房源，后续分页处理需引入Selenium，因为某些网站可能会加载更多房源需要JavaScript
    houses = parse_page(get_html(base_url))
    
    # 需要使用Selenium模拟点击下一页，这里仅提供思路，实际实现依赖于搜房网的具体结构
    next_button_xpath = '//a[contains(text(), "下一页")]'
    while True:
        try:
            # 模拟点击下一页
            options = ChromeOptions()
            driver = Chrome(options=options)
            driver.get(base_url)
            next_button = driver.find_element_by_xpath(next_button_xpath)
            next_button.click()
            
            # 获取新页面的HTML
            new_html = driver.page_source
            driver.quit()

            # 解析新页面
            new_houses = parse_page(new_html)
            houses.extend(new_houses)

            # 如果没有找到“下一页”，则停止循环
            if not next_button.is_displayed():
                break
        except Exception as e:
            print(f"Failed to load more pages: {e}")
            break

    return houses

all_houses = fetch_all_houses()
for house in all_houses:
    print(house)