如何在不附加键的情况下将字典附加到 csv

Question

我有一个字典 features = {'feature1' : 'hi', 'feature2': 'second feature', 'feature3': 'third feature'}。我需要将其保存到 csv 文件中。但是这个字典在每次迭代中都会更新，并且一个新的字典会附加到现有的 csv 文件中。我在scrapy中使用它。

class Myspider(SitemapSpider):
    name = 'spidername'
    sitemap_urls = ['https://www.arabam.com/sitemap/otomobil_1.xml']
    sitemap_rules = [
        ('/otomobil/', 'parse'),
        # ('/category/', 'parse_category'),
    ]

    def parse(self,response):


                            yield scrapy.Request(url, callback=self.parse_dir_contents)

    def parse_dir_contents(self,response):
        # print("hi here")
        features = {}
        features["ad_url"] = response.request.url
        #filling feature dictionary
        df = pd.DataFrame.from_dict(features , orient='index')
        df = df.transpose()
        df.to_csv("result.csv",mode = 'a', index = False)

问题是这会将字典和键一起保存到 csv 中。我在这里附上excel表的图片： enter image description here

直观地说，标题应该只在顶部填充一次，而不是每隔一行。我该怎么做？

Answer 1

class Myspider(SitemapSpider):
    name = 'spidername'
    sitemap_urls = ['https://www.arabam.com/sitemap/otomobil_1.xml']
    sitemap_rules = [
        ('/otomobil/', 'parse'),
        # ('/category/', 'parse_category'),
    ]
    custom_settings = {'FEED_FORMAT':'csv','FEED_URI':'FILEname.csv'}

    def parse(self,response):


        yield scrapy.Request(url, callback=self.parse_dir_contents)

    def parse_dir_contents(self,response):
        # print("hi here")
        item = {}
        item["ad_url"] = response.request.url
        yield item

运行它scrapy crawl spidername