爬虫遇到了问题：name 'headers' is not defined，请问如何解决？

爬虫遇到了问题：name 'headers' is not defined，请问如何解决？

from lxml import etree
import requests
import csv
import time
def spider():
    headers = {
        'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.81 Safari/537.36 SE 2.X MetaSr 1.0'
        }
pre_url='https://hefei.qfang.com/rent/f'
for x in range(1,13):
    html=requests.get(pre_url+str(x),headers=headers)
    time.sleep(2)#在每一次GET后，等待2秒
    selector=etree.HTML(html.text)
#先获取房源列表
house_list=selector.xpath("//*[@id='cycleListings']/ul/li")
for house in house_list:
    xiaoqu=house.xpath("div[2]/div[3]/div/a/text()")[0]
    huxing=house.xpath("div[2]/div[2]/p[1]/text()")[0]
    area=house.xpath("div[2]/div[2]/p[2]/text()")[0]
    month_price=house.xpath("div[3]/p/span[1]/text()")[0]
    people=house.xpath("div/div[2]/div[4]/div[1]/p/a/text()")[0]
    people_picture=house.xpath("/div/div[2]/div[4]/p/a/img/text()")[0]
item=[xiaoqu,huxing,area,month_price,people,people_picture]
data_writer(item)
print('正在抓取',xiaoqu)
def data_writer(item):
    with open()as csvfile:
        writer=csv.writer(csvfile)
        writer.writerow(item)
if __name__ == '__main__':
    spider()

缩进有问题：

from lxml import etree
import requests
import csv
import time


def spider():
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.81 Safari/537.36 SE 2.X MetaSr 1.0'
    }

    
    pre_url = 'https://hefei.qfang.com/rent/f'
    for x in range(1, 13):
        html = requests.get(pre_url + str(x), headers=headers)
        time.sleep(2)  # 在每一次GET后，等待2秒
        selector = etree.HTML(html.text)
    # 先获取房源列表
    house_list = selector.xpath("//*[@id='cycleListings']/ul/li")
    for house in house_list:
        xiaoqu = house.xpath("div[2]/div[3]/div/a/text()")[0]
        huxing = house.xpath("div[2]/div[2]/p[1]/text()")[0]
        area = house.xpath("div[2]/div[2]/p[2]/text()")[0]
        month_price = house.xpath("div[3]/p/span[1]/text()")[0]
        people = house.xpath("div/div[2]/div[4]/div[1]/p/a/text()")[0]
        people_picture = house.xpath("/div/div[2]/div[4]/p/a/img/text()")[0]
    item = [xiaoqu, huxing, area, month_price, people, people_picture]
    data_writer(item)
    print('正在抓取', xiaoqu)


def data_writer(item):
    with open()as csvfile:
        writer = csv.writer(csvfile)
        writer.writerow(item)


if __name__ == '__main__':
    spider()

has no attribute 'items'引用的对象没有这个属性

headers下面数据请求整体缩进一下，他是在方法里，你那都放到方法外面了