Python 如何在输出到CSV之前剥离碎片结果

我试图从一些HTML中分离出整数，例如“
5500英里
“

import scrapy

class AlfaShortSpider(scrapy.Spider):
    name = 'alfashort'

    def start_requests(self):
        yield scrapy.Request(url = 'https://www.pistonheads.com/classifieds/used-cars/alfa-romeo/giulia',
                             callback = self.parse_data)


    def parse_data( self, response ):
        advert = response.xpath( '//*[@class="ad-listing"]')
        title = advert.xpath( './/*[@class="listing-headline"]//h3/text()' ).extract()
        price = advert.xpath( './/*[@class="price"]/text()' ).extract()
        mileage = advert.xpath( './/*[@class="specs"]//li[1]/text()' ).extract()
        mileage = [item.strip() for item in mileage]
        mileage = [item.replace(',','') for item in mileage]
        mileage = [item.replace(' miles','') for item in mileage]

        for item in zip(title,price,mileage):
            price_data = {
                    'title' : item[0],
                    'price' : item[1],
                    'mileage' : item[2]
            }

            yield price_data 

我的代码成功地删除了逗号和“英里”，但在CSV输出中，我在该列中得到了不需要的空行，我认为这是由于原始源中的回车。我的CSV如下所示：

所以标题和价格栏都很好。但“里程”列是错误所在

import scrapy

class AlfaShortSpider(scrapy.Spider):
    name = 'alfashort'

    def start_requests(self):
        yield scrapy.Request(url = 'https://www.pistonheads.com/classifieds/used-cars/alfa-romeo/giulia',
                             callback = self.parse_data)


    def parse_data( self, response ):
        advert = response.xpath( '//*[@class="ad-listing"]')
        title = advert.xpath( './/*[@class="listing-headline"]//h3/text()' ).extract()
        price = advert.xpath( './/*[@class="price"]/text()' ).extract()
        mileage = advert.xpath( './/*[@class="specs"]//li[1]/text()' ).extract()
        mileage = [item.strip() for item in mileage]
        mileage = [item.replace(',','') for item in mileage]
        mileage = [item.replace(' miles','') for item in mileage]

        for item in zip(title,price,mileage):
            price_data = {
                    'title' : item[0],
                    'price' : item[1],
                    'mileage' : item[2]
            }

            yield price_data 

---

我的Strip命令有问题吗？

只需更改里程数的XPath即可

从

到

您将获得正确的输出：

title,price,mileage
ALFA ROMEO GIULIA (0) V6 BITURBO QUADRIFOGLIO                  2018 (2018),"£48,500",5500
ULEZ CHARGE EXEMPT! EURO 6  (2017),"£25,695",11450
ALFA ROMEO GIULIA (0) V6 BITURBO QUADRIFOGLIO NRING            2019 (2019),"£83,500",100
ALFA ROMEO GIULIA (0) TD SPECIALE                              2017 (2017),"£22,500",23700

---

您可以使用查找意外事件发生的时间点。您应该调试

milage

为空时的响应。也许你的请求被某种方式阻止了？你的csv看起来像这样吗？我添加了一个csv输出的屏幕截图。只有“里程”列插入了空行。所以，不仅一些里程数丢失了，其中的里程数和其他数据不一致。这是有效的。非常感谢你。你能解释一下这是怎么回事吗？我不熟悉XPath，但我的理解是[2]选择了该类型的第二个对象，但在我看来，每个/li/只有一个文本对象。如果答案有效，请接受。在第一个对象中，该值为空。

title,price,mileage
ALFA ROMEO GIULIA (0) V6 BITURBO QUADRIFOGLIO                  2018 (2018),"£48,500",5500
ULEZ CHARGE EXEMPT! EURO 6  (2017),"£25,695",11450
ALFA ROMEO GIULIA (0) V6 BITURBO QUADRIFOGLIO NRING            2019 (2019),"£83,500",100
ALFA ROMEO GIULIA (0) TD SPECIALE                              2017 (2017),"£22,500",23700