Python 导出到Excel时会覆盖数据

我正在浏览一个网站，根据一些关键词收集最近的十篇文章。一旦我得到我的数据（使用的关键字、文章名称、URL/超链接和发布日期），我想将其全部写入xls文件。到目前为止，它只写最后一个关键字的结果，而不是所有四个关键字，它只是覆盖了电子表格的同一部分。如何显示整个列表，而不仅仅是最近的部分

import requests
from bs4 import BeautifulSoup
import datetime
import xlwt
from xlwt import Formula


today = datetime.date.today().strftime("%Y%m%d")

keywords = ('PNC', 'Huntington', 'KeyCorp', 'Fifth Third')

for keyword in keywords:
    keyword.replace("+", " ")

headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64)       AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36'}

def article_fetch(keyword):
    url = 'https://www.americanbanker.com/search?query={}'.format(keyword)
    r = requests.get(url, headers = headers)

    soup = BeautifulSoup(r.text, 'html.parser')

    mylist = []
    cols = "KeyWord", "Article", "URL", "Publication Date"
    mylist.append(cols)
    for articles in soup.find_all("div", "feed-item"):
        article = articles.find("h4").text.strip()
        timestamp = articles.find("span", "timestamp").text.strip()
        article_url = 'https://{}'.format(articles.find("a")["href"][2:])
        link = 'HYPERLINK("{}", "Link" )'.format(article_url)
        item = [keyword, article, Formula(link), timestamp]
        mylist.append(item)


        book = xlwt.Workbook()
        sheet = book.add_sheet("Articles")
        for i, row in enumerate(mylist):
            for j, col in enumerate(row):
                sheet.write(i, j, col)
        book.save("C:\Python\American Banker\American Banker {}.xls".format(today))


for keyword in keywords:
    article_fetch(keyword)

print('Workbook Saved')

---

我希望看到我的整个列表，其中包含所有四个关键字的结果。但是，我只看到最后一个关键字的结果。

我已将Excel文件生成移到脚本末尾：

import requests
from bs4 import BeautifulSoup
import datetime
import xlwt
from xlwt import Formula


today = datetime.date.today().strftime("%Y%m%d")

keywords = ('PNC', 'Huntington', 'KeyCorp', 'Fifth Third')

for keyword in keywords:
    keyword.replace("+", " ")

headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64)       AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36'}


def article_fetch(keyword):
    url = 'https://www.americanbanker.com/search?query={}'.format(keyword)
    r = requests.get(url, headers = headers)

    soup = BeautifulSoup(r.text, 'html.parser')

    for articles in soup.find_all("div", "feed-item"):
        article = articles.find("h4").text.strip()
        timestamp = articles.find("span", "timestamp").text.strip()
        article_url = 'https://{}'.format(articles.find("a")["href"][2:])
        link = 'HYPERLINK("{}", "Link" )'.format(article_url)
        item = [keyword, article, Formula(link), timestamp]
        mylist.append(item)


mylist = []
cols = "KeyWord", "Article", "URL", "Publication Date"
mylist.append(cols)
for keyword in keywords:
    article_fetch(keyword)

book = xlwt.Workbook()
sheet = book.add_sheet('Articles')
for i, row in enumerate(mylist):
    for j, col in enumerate(row):
        sheet.write(i, j, col)
book.save("American Banker {}.xls".format(today))

print('Workbook Saved')

数据将不再丢失：