如何使用If then语句读取csv值？

Question

我想读取'Rel volume'的csv文件值，然后打印代码和值，如果值为2.5或更大。但是，我不能这样做，因为int值无法与'str'值进行比较。如何比较这些值，然后将来自相应股票代码的csv文件的值放入新列表中？这是我的代码：

import csv
import urllib.request
from bs4 import BeautifulSoup


write_header = True

twiturl = "https://twitter.com/ACInvestorBlog"
twitpage = urllib.request.urlopen(twiturl)
soup = BeautifulSoup(twitpage,"html.parser")

print(soup.title.text)

tweets = [i.text for i in soup.select('a.twitter-cashtag.pretty-link.js-nav b')]
""""
print(tweets)
"""
URL_BASE = "https://finviz.com/quote.ashx?t="

with open('_Stocks.csv', 'w', newline='') as file:
    writer = csv.writer(file)

    # note the change
    for tckr in tweets:
        URL = URL_BASE + tckr
        try:
            fpage = urllib.request.urlopen(URL)
            fsoup = BeautifulSoup(fpage, 'html.parser')

            if write_header:
                # note the change
                writer.writerow(['tckr'] + list(map(lambda e: e.text, fsoup.find_all('td', {'class': 'snapshot-td2-cp'}))))
                write_header = False

            # note the change
            writer.writerow([tckr] + list(map(lambda e: e.text, fsoup.find_all('td', {'class': 'snapshot-td2'}))))
        except urllib.request.HTTPError:
            print("{} - not found".format(URL))

with open('_Stocks.csv') as csv_file:
    csv_reader = csv.DictReader(csv_file)

    for line in csv_reader:
        if line['Rel Volume'] > 2.5:
            print(line['tckr'], line['Rel Volume'])

Answer 1

使用csv.DictReader()读取数据时，值都是字符串。因此，您需要在使用之前将Rel Volume转换为浮点数：

with open('_Stocks.csv', newline='') as csv_file:
    csv_reader = csv.DictReader(csv_file)

    for line in csv_reader:
        line['Rel Volume'] = float(line['Rel Volume'])

        if line['Rel Volume'] > 2.5:
            print(line['tckr'], line['Rel Volume'])